1 /*
2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "code/nmethod.hpp"
29 #include "compiler/compilationPolicy.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "interpreter/linkResolver.hpp"
33 #include "memory/universe.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 #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 // Do this after the transition because this allows us to put an assert
120 // the Java->vm transition which checks to see that stack is not walkable
121 // on sparc/ia64 which will catch violations of the resetting of last_Java_frame
122 // invariants (i.e. _flags always cleared on return to Java)
123
124 _thread->frame_anchor()->copy(&_anchor);
125
126 // Release handles after we are marked as being inside the VM again, since this
127 // operation might block
128 JNIHandleBlock::release_block(_old_handles, _thread);
129
130 if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
131 // If we get here, the Java code threw an exception that unwound a frame.
132 // It could be that the new frame anchor has not passed through the required
133 // StackWatermark barriers. Therefore, we process any such deferred unwind
134 // requests here.
135 StackWatermarkSet::after_unwind(_thread);
136 }
137 }
138
139
140 void JavaCallWrapper::oops_do(OopClosure* f) {
141 f->do_oop((oop*)&_receiver);
142 handles()->oops_do(f);
143 }
144
145
146 // Helper methods
147 static BasicType runtime_type_from(JavaValue* result) {
148 switch (result->get_type()) {
149 case T_BOOLEAN: // fall through
150 case T_CHAR : // fall through
151 case T_SHORT : // fall through
152 case T_INT : // fall through
153 #ifndef _LP64
154 case T_OBJECT : // fall through
155 case T_ARRAY : // fall through
156 #endif
157 case T_BYTE : // fall through
158 case T_VOID : return T_INT;
159 case T_LONG : return T_LONG;
160 case T_FLOAT : return T_FLOAT;
161 case T_DOUBLE : return T_DOUBLE;
162 #ifdef _LP64
163 case T_ARRAY : // fall through
164 case T_OBJECT: return T_OBJECT;
165 #endif
166 default:
167 ShouldNotReachHere();
168 return T_ILLEGAL;
169 }
170 }
171
172 // ============ Virtual calls ============
173
174 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
175 CallInfo callinfo;
176 Handle receiver = args->receiver();
177 Klass* recvrKlass = receiver.is_null() ? (Klass*)nullptr : receiver->klass();
178 LinkInfo link_info(spec_klass, name, signature);
179 LinkResolver::resolve_virtual_call(
180 callinfo, receiver, recvrKlass, link_info, true, CHECK);
181 methodHandle method(THREAD, callinfo.selected_method());
182 assert(method.not_null(), "should have thrown exception");
183
184 // Invoke the method
185 JavaCalls::call(result, method, args, CHECK);
186 }
187
188
189 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
190 JavaCallArguments args(receiver);
191 call_virtual(result, spec_klass, name, signature, &args, CHECK);
192 }
193
194
195 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
196 JavaCallArguments args(receiver);
197 args.push_oop(arg1);
198 call_virtual(result, spec_klass, name, signature, &args, CHECK);
199 }
200
201
202
203 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
204 JavaCallArguments args(receiver);
205 args.push_oop(arg1);
206 args.push_oop(arg2);
207 call_virtual(result, spec_klass, name, signature, &args, CHECK);
208 }
209
210
211 // ============ Special calls ============
212
213 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
214 CallInfo callinfo;
215 LinkInfo link_info(klass, name, signature);
216 LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
217 methodHandle method(THREAD, callinfo.selected_method());
218 assert(method.not_null(), "should have thrown exception");
219
220 // Invoke the method
221 JavaCalls::call(result, method, args, CHECK);
222 }
223
224
225 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
226 JavaCallArguments args(receiver);
227 call_special(result, klass, name, signature, &args, CHECK);
228 }
229
230
231 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
232 JavaCallArguments args(receiver);
233 args.push_oop(arg1);
234 call_special(result, klass, name, signature, &args, CHECK);
235 }
236
237
238 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
239 JavaCallArguments args(receiver);
240 args.push_oop(arg1);
241 args.push_oop(arg2);
242 call_special(result, klass, name, signature, &args, CHECK);
243 }
244
245
246 // ============ Static calls ============
247
248 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
249 CallInfo callinfo;
250 LinkInfo link_info(klass, name, signature);
251 LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);
252 methodHandle method(THREAD, callinfo.selected_method());
253 assert(method.not_null(), "should have thrown exception");
254
255 // Invoke the method
256 JavaCalls::call(result, method, args, CHECK);
257 }
258
259
260 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
261 JavaCallArguments args;
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, TRAPS) {
267 JavaCallArguments args(arg1);
268 call_static(result, klass, name, signature, &args, CHECK);
269 }
270
271
272 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
273 JavaCallArguments args;
274 args.push_oop(arg1);
275 args.push_oop(arg2);
276 call_static(result, klass, name, signature, &args, CHECK);
277 }
278
279
280 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
281 JavaCallArguments args;
282 args.push_oop(arg1);
283 args.push_oop(arg2);
284 args.push_oop(arg3);
285 call_static(result, klass, name, signature, &args, CHECK);
286 }
287
288 // ============ allocate and initialize new object instance ============
289
290 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
291 klass->initialize(CHECK_NH); // Quick no-op if already initialized.
292 Handle obj = klass->allocate_instance_handle(CHECK_NH);
293 JavaValue void_result(T_VOID);
294 args->set_receiver(obj); // inserts <obj> as the first argument.
295 JavaCalls::call_special(&void_result, klass,
296 vmSymbols::object_initializer_name(),
297 constructor_signature, args, CHECK_NH);
298 // Already returned a Null Handle if any exception is pending.
299 return obj;
300 }
301
302 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
303 JavaCallArguments args;
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, TRAPS) {
308 JavaCallArguments args;
309 args.push_oop(arg1);
310 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
311 }
312
313 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
314 JavaCallArguments args;
315 args.push_oop(arg1);
316 args.push_oop(arg2);
317 return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
318 }
319
320 // -------------------------------------------------
321 // Implementation of JavaCalls (low level)
322
323
324 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
325 // Check if we need to wrap a potential OS exception handler around thread.
326 // This is used for e.g. Win32 structured exception handlers.
327 // Need to wrap each and every time, since there might be native code down the
328 // stack that has installed its own exception handlers.
329 os::os_exception_wrapper(call_helper, result, method, args, THREAD);
330 }
331
332 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
333
334 JavaThread* thread = THREAD;
335 assert(method.not_null(), "must have a method to call");
336 assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
337 assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
338
339 // Verify the arguments
340 if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
341 args->verify(method, result->get_type());
342 }
343 // Ignore call if method is empty
344 if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
345 assert(result->get_type() == T_VOID, "an empty method must return a void value");
346 return;
347 }
348
349 #ifdef ASSERT
350 { InstanceKlass* holder = method->method_holder();
351 // A klass might not be initialized since JavaCall's might be used during the executing of
352 // the <clinit>. For example, a Thread.start might start executing on an object that is
353 // not fully initialized! (bad Java programming style)
354 assert(holder->is_linked(), "rewriting must have taken place");
355 }
356 #endif
357
358 CompilationPolicy::compile_if_required(method, CHECK);
359
360 // Figure out if the result value is an oop or not (Note: This is a different value
361 // than result_type. result_type will be T_INT of oops. (it is about size)
362 BasicType result_type = runtime_type_from(result);
363 bool oop_result_flag = is_reference_type(result->get_type());
364
365 // Find receiver
366 Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
367
368 // When we reenter Java, we need to re-enable the reserved/yellow zone which
369 // might already be disabled when we are in VM.
370 thread->stack_overflow_state()->reguard_stack_if_needed();
371
372 // Check that there are shadow pages available before changing thread state
373 // to Java. Calculate current_stack_pointer here to make sure
374 // stack_shadow_pages_available() and map_stack_shadow_pages() use the same sp.
375 address sp = os::current_stack_pointer();
376 if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
377 // Throw stack overflow exception with preinitialized exception.
378 Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
379 return;
380 } else {
381 // Touch pages checked if the OS needs them to be touched to be mapped.
382 os::map_stack_shadow_pages(sp);
383 }
384
385 // do call
386 { JavaCallWrapper link(method, receiver, result, CHECK);
387 { HandleMark hm(thread); // HandleMark used by HandleMarkCleaner
388
389 // NOTE: if we move the computation of the result_val_address inside
390 // the call to call_stub, the optimizer produces wrong code.
391 intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
392 intptr_t* parameter_address = args->parameters();
393
394 address entry_point;
395 {
396 // The enter_interp_only_mode use handshake to set interp_only mode
397 // so no safepoint should be allowed between is_interp_only_mode() and call
398 NoSafepointVerifier nsv;
399 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
400 entry_point = method->interpreter_entry();
401 } else {
402 // Since the call stub sets up like the interpreter we call the from_interpreted_entry
403 // so we can go compiled via a i2c.
404 entry_point = method->from_interpreted_entry();
405 #if INCLUDE_JVMCI
406 // Gets the alternative target (if any) that should be called
407 Handle alternative_target = args->alternative_target();
408 if (!alternative_target.is_null()) {
409 // Must extract verified entry point from HotSpotNmethod after VM to Java
410 // transition in JavaCallWrapper constructor so that it is safe with
411 // respect to nmethod sweeping.
412 address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(nullptr, alternative_target());
413 if (verified_entry_point != nullptr) {
414 thread->set_jvmci_alternate_call_target(verified_entry_point);
415 entry_point = method->adapter()->get_i2c_entry();
416 }
417 }
418 #endif
419 }
420 }
421 StubRoutines::call_stub()(
422 (address)&link,
423 // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
424 result_val_address, // see NOTE above (compiler problem)
425 result_type,
426 method(),
427 entry_point,
428 parameter_address,
429 args->size_of_parameters(),
430 CHECK
431 );
432
433 result = link.result(); // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
434 // Preserve oop return value across possible gc points
435 if (oop_result_flag) {
436 thread->set_vm_result(result->get_oop());
437 }
438 }
439 } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
440
441 // Check if a thread stop or suspend should be executed
442 // The following assert was not realistic. Thread.stop can set that bit at any moment.
443 //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
444
445 // Restore possible oop return
446 if (oop_result_flag) {
447 result->set_oop(thread->vm_result());
448 thread->set_vm_result(nullptr);
449 }
450 }
451
452
453 //--------------------------------------------------------------------------------------
454 // Implementation of JavaCallArguments
455
456 inline bool is_value_state_indirect_oop(uint state) {
457 assert(state != JavaCallArguments::value_state_oop,
458 "Checking for handles after removal");
459 assert(state < JavaCallArguments::value_state_limit,
460 "Invalid value state %u", state);
461 return state != JavaCallArguments::value_state_primitive;
462 }
463
464 inline oop resolve_indirect_oop(intptr_t value, uint state) {
465 switch (state) {
466 case JavaCallArguments::value_state_handle:
467 {
468 oop* ptr = reinterpret_cast<oop*>(value);
469 return Handle::raw_resolve(ptr);
470 }
471
472 case JavaCallArguments::value_state_jobject:
473 {
474 jobject obj = reinterpret_cast<jobject>(value);
475 return JNIHandles::resolve(obj);
476 }
477
478 default:
479 ShouldNotReachHere();
480 return nullptr;
481 }
482 }
483
484 intptr_t* JavaCallArguments::parameters() {
485 // First convert all handles to oops
486 for(int i = 0; i < _size; i++) {
487 uint state = _value_state[i];
488 assert(state != value_state_oop, "Multiple handle conversions");
489 if (is_value_state_indirect_oop(state)) {
490 oop obj = resolve_indirect_oop(_value[i], state);
491 _value[i] = cast_from_oop<intptr_t>(obj);
492 _value_state[i] = value_state_oop;
493 }
494 }
495 // Return argument vector
496 return _value;
497 }
498
499
500 class SignatureChekker : public SignatureIterator {
501 private:
502 int _pos;
503 BasicType _return_type;
504 u_char* _value_state;
505 intptr_t* _value;
506
507 public:
508 SignatureChekker(Symbol* signature,
509 BasicType return_type,
510 bool is_static,
511 u_char* value_state,
512 intptr_t* value) :
513 SignatureIterator(signature),
514 _pos(0),
515 _return_type(return_type),
516 _value_state(value_state),
517 _value(value)
518 {
519 if (!is_static) {
520 check_value(true); // Receiver must be an oop
521 }
522 do_parameters_on(this);
523 check_return_type(return_type);
524 }
525
526 private:
527 void check_value(bool is_reference) {
528 uint state = _value_state[_pos++];
529 if (is_reference) {
530 guarantee(is_value_state_indirect_oop(state),
531 "signature does not match pushed arguments: %u at %d",
532 state, _pos - 1);
533 } else {
534 guarantee(state == JavaCallArguments::value_state_primitive,
535 "signature does not match pushed arguments: %u at %d",
536 state, _pos - 1);
537 }
538 }
539
540 void check_return_type(BasicType t) {
541 guarantee(t == _return_type, "return type does not match");
542 }
543
544 void check_single_word() {
545 check_value(false);
546 }
547
548 void check_double_word() {
549 check_value(false);
550 check_value(false);
551 }
552
553 void check_reference() {
554 intptr_t v = _value[_pos];
555 if (v != 0) {
556 // v is a "handle" referring to an oop, cast to integral type.
557 // There shouldn't be any handles in very low memory.
558 guarantee((size_t)v >= os::vm_page_size(),
559 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
560 // Verify the pointee.
561 oop vv = resolve_indirect_oop(v, _value_state[_pos]);
562 guarantee(oopDesc::is_oop_or_null(vv, true),
563 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
564 _pos, v, p2i(vv));
565 }
566
567 check_value(true); // Verify value state.
568 }
569
570 friend class SignatureIterator; // so do_parameters_on can call do_type
571 void do_type(BasicType type) {
572 switch (type) {
573 case T_BYTE:
574 case T_BOOLEAN:
575 case T_CHAR:
576 case T_SHORT:
577 case T_INT:
578 case T_FLOAT: // this one also
579 check_single_word(); break;
580 case T_LONG:
581 case T_DOUBLE:
582 check_double_word(); break;
583 case T_ARRAY:
584 case T_OBJECT:
585 check_reference(); break;
586 default:
587 ShouldNotReachHere();
588 }
589 }
590 };
591
592
593 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
594 guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
595
596 // Treat T_OBJECT and T_ARRAY as the same
597 if (is_reference_type(return_type)) return_type = T_OBJECT;
598
599 // Check that oop information is correct
600 Symbol* signature = method->signature();
601
602 SignatureChekker sc(signature,
603 return_type,
604 method->is_static(),
605 _value_state,
606 _value);
607 }