1 /*
  2  * Copyright (c) 1997, 2021, 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 #if INCLUDE_JVMCI
 34 #include "jvmci/jvmciJavaClasses.hpp"
 35 #endif
 36 #include "memory/universe.hpp"
 37 #include "oops/method.inline.hpp"
 38 #include "oops/oop.inline.hpp"
 39 #include "prims/jniCheck.hpp"
 40 #include "prims/jvmtiExport.hpp"
 41 #include "runtime/handles.inline.hpp"
 42 #include "runtime/interfaceSupport.inline.hpp"
 43 #include "runtime/javaCalls.hpp"
 44 #include "runtime/jniHandles.inline.hpp"
 45 #include "runtime/mutexLocker.hpp"
 46 #include "runtime/os.inline.hpp"
 47 #include "runtime/sharedRuntime.hpp"
 48 #include "runtime/signature.hpp"
 49 #include "runtime/stubRoutines.hpp"
 50 #include "runtime/thread.inline.hpp"
 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 == NULL 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   assert (_thread->thread_state() != _thread_in_native, "cannot set native pc to NULL");
 98 
 99   MACOS_AARCH64_ONLY(_thread->enable_wx(WXExec));
100 }
101 
102 
103 JavaCallWrapper::~JavaCallWrapper() {
104   assert(_thread == JavaThread::current(), "must still be the same thread");
105 
106   MACOS_AARCH64_ONLY(_thread->enable_wx(WXWrite));
107 
108   // restore previous handle block & Java frame linkage
109   JNIHandleBlock *_old_handles = _thread->active_handles();
110   _thread->set_active_handles(_handles);
111 
112   _thread->frame_anchor()->zap();
113 
114   debug_only(_thread->dec_java_call_counter());
115 
116   // Old thread-local info. has been restored. We are not back in the VM.
117   ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
118 
119   // State has been restored now make the anchor frame visible for the profiler.
120   // Do this after the transition because this allows us to put an assert
121   // the Java->vm transition which checks to see that stack is not walkable
122   // on sparc/ia64 which will catch violations of the reseting of last_Java_frame
123   // invariants (i.e. _flags always cleared on return to Java)
124 
125   _thread->frame_anchor()->copy(&_anchor);
126 
127   // Release handles after we are marked as being inside the VM again, since this
128   // operation might block
129   JNIHandleBlock::release_block(_old_handles, _thread);
130 
131   if (_thread->has_pending_exception() && _thread->has_last_Java_frame()) {
132     // If we get here, the Java code threw an exception that unwound a frame.
133     // It could be that the new frame anchor has not passed through the required
134     // StackWatermark barriers. Therefore, we process any such deferred unwind
135     // requests here.
136     StackWatermarkSet::after_unwind(_thread);
137   }
138 }
139 
140 
141 void JavaCallWrapper::oops_do(OopClosure* f) {
142   f->do_oop((oop*)&_receiver);
143   handles()->oops_do(f);
144 }
145 
146 
147 // Helper methods
148 static BasicType runtime_type_from(JavaValue* result) {
149   switch (result->get_type()) {
150     case T_BOOLEAN: // fall through
151     case T_CHAR   : // fall through
152     case T_SHORT  : // fall through
153     case T_INT    : // fall through
154 #ifndef _LP64
155     case T_OBJECT : // fall through
156     case T_ARRAY  : // fall through
157 #endif
158     case T_BYTE   : // fall through
159     case T_VOID   : return T_INT;
160     case T_LONG   : return T_LONG;
161     case T_FLOAT  : return T_FLOAT;
162     case T_DOUBLE : return T_DOUBLE;
163 #ifdef _LP64
164     case T_ARRAY  : // fall through
165     case T_OBJECT:  return T_OBJECT;
166 #endif
167     default:
168       ShouldNotReachHere();
169       return T_ILLEGAL;
170   }
171 }
172 
173 // ============ Virtual calls ============
174 
175 void JavaCalls::call_virtual(JavaValue* result, Klass* spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
176   CallInfo callinfo;
177   Handle receiver = args->receiver();
178   Klass* recvrKlass = receiver.is_null() ? (Klass*)NULL : receiver->klass();
179   LinkInfo link_info(spec_klass, name, signature);
180   LinkResolver::resolve_virtual_call(
181           callinfo, receiver, recvrKlass, link_info, true, CHECK);
182   methodHandle method(THREAD, callinfo.selected_method());
183   assert(method.not_null(), "should have thrown exception");
184 
185   // Invoke the method
186   JavaCalls::call(result, method, args, CHECK);
187 }
188 
189 
190 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, TRAPS) {
191   JavaCallArguments args(receiver);
192   call_virtual(result, spec_klass, name, signature, &args, CHECK);
193 }
194 
195 
196 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
197   JavaCallArguments args(receiver);
198   args.push_oop(arg1);
199   call_virtual(result, spec_klass, name, signature, &args, CHECK);
200 }
201 
202 
203 
204 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, Klass* spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
205   JavaCallArguments args(receiver);
206   args.push_oop(arg1);
207   args.push_oop(arg2);
208   call_virtual(result, spec_klass, name, signature, &args, CHECK);
209 }
210 
211 
212 // ============ Special calls ============
213 
214 void JavaCalls::call_special(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
215   CallInfo callinfo;
216   LinkInfo link_info(klass, name, signature);
217   LinkResolver::resolve_special_call(callinfo, args->receiver(), link_info, CHECK);
218   methodHandle method(THREAD, callinfo.selected_method());
219   assert(method.not_null(), "should have thrown exception");
220 
221   // Invoke the method
222   JavaCalls::call(result, method, args, CHECK);
223 }
224 
225 
226 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
227   JavaCallArguments args(receiver);
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, TRAPS) {
233   JavaCallArguments args(receiver);
234   args.push_oop(arg1);
235   call_special(result, klass, name, signature, &args, CHECK);
236 }
237 
238 
239 void JavaCalls::call_special(JavaValue* result, Handle receiver, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
240   JavaCallArguments args(receiver);
241   args.push_oop(arg1);
242   args.push_oop(arg2);
243   call_special(result, klass, name, signature, &args, CHECK);
244 }
245 
246 
247 // ============ Static calls ============
248 
249 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
250   CallInfo callinfo;
251   LinkInfo link_info(klass, name, signature);
252   LinkResolver::resolve_static_call(callinfo, link_info, true, CHECK);
253   methodHandle method(THREAD, callinfo.selected_method());
254   assert(method.not_null(), "should have thrown exception");
255 
256   // Invoke the method
257   JavaCalls::call(result, method, args, CHECK);
258 }
259 
260 
261 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, TRAPS) {
262   JavaCallArguments args;
263   call_static(result, klass, name, signature, &args, CHECK);
264 }
265 
266 
267 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
268   JavaCallArguments args(arg1);
269   call_static(result, klass, name, signature, &args, CHECK);
270 }
271 
272 
273 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
274   JavaCallArguments args;
275   args.push_oop(arg1);
276   args.push_oop(arg2);
277   call_static(result, klass, name, signature, &args, CHECK);
278 }
279 
280 
281 void JavaCalls::call_static(JavaValue* result, Klass* klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, Handle arg3, TRAPS) {
282   JavaCallArguments args;
283   args.push_oop(arg1);
284   args.push_oop(arg2);
285   args.push_oop(arg3);
286   call_static(result, klass, name, signature, &args, CHECK);
287 }
288 
289 // ============ allocate and initialize new object instance ============
290 
291 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, JavaCallArguments* args, TRAPS) {
292   klass->initialize(CHECK_NH); // Quick no-op if already initialized.
293   Handle obj = klass->allocate_instance_handle(CHECK_NH);
294   JavaValue void_result(T_VOID);
295   args->set_receiver(obj); // inserts <obj> as the first argument.
296   JavaCalls::call_special(&void_result, klass,
297                           vmSymbols::object_initializer_name(),
298                           constructor_signature, args, CHECK_NH);
299   // Already returned a Null Handle if any exception is pending.
300   return obj;
301 }
302 
303 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, TRAPS) {
304   JavaCallArguments args;
305   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
306 }
307 
308 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, TRAPS) {
309   JavaCallArguments args;
310   args.push_oop(arg1);
311   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
312 }
313 
314 Handle JavaCalls::construct_new_instance(InstanceKlass* klass, Symbol* constructor_signature, Handle arg1, Handle arg2, TRAPS) {
315   JavaCallArguments args;
316   args.push_oop(arg1);
317   args.push_oop(arg2);
318   return JavaCalls::construct_new_instance(klass, constructor_signature, &args, THREAD);
319 }
320 
321 // -------------------------------------------------
322 // Implementation of JavaCalls (low level)
323 
324 
325 void JavaCalls::call(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
326   // Check if we need to wrap a potential OS exception handler around thread.
327   // This is used for e.g. Win32 structured exception handlers.
328   // Need to wrap each and every time, since there might be native code down the
329   // stack that has installed its own exception handlers.
330   os::os_exception_wrapper(call_helper, result, method, args, THREAD);
331 }
332 
333 void JavaCalls::call_helper(JavaValue* result, const methodHandle& method, JavaCallArguments* args, TRAPS) {
334 
335   JavaThread* thread = THREAD;
336   assert(method.not_null(), "must have a method to call");
337   assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
338   assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
339 
340   // Verify the arguments
341   if (JVMCI_ONLY(args->alternative_target().is_null() &&) (DEBUG_ONLY(true ||) CheckJNICalls)) {
342     args->verify(method, result->get_type());
343   }
344   // Ignore call if method is empty
345   if (JVMCI_ONLY(args->alternative_target().is_null() &&) method->is_empty_method()) {
346     assert(result->get_type() == T_VOID, "an empty method must return a void value");
347     return;
348   }
349 
350 #ifdef ASSERT
351   { InstanceKlass* holder = method->method_holder();
352     // A klass might not be initialized since JavaCall's might be used during the executing of
353     // the <clinit>. For example, a Thread.start might start executing on an object that is
354     // not fully initialized! (bad Java programming style)
355     assert(holder->is_linked(), "rewriting must have taken place");
356   }
357 #endif
358 
359   CompilationPolicy::compile_if_required(method, CHECK);
360 
361   // Since the call stub sets up like the interpreter we call the from_interpreted_entry
362   // so we can go compiled via a i2c. Otherwise initial entry method will always
363   // run interpreted.
364   address entry_point = method->from_interpreted_entry();
365   if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
366     entry_point = method->interpreter_entry();
367   }
368 
369   // Figure out if the result value is an oop or not (Note: This is a different value
370   // than result_type. result_type will be T_INT of oops. (it is about size)
371   BasicType result_type = runtime_type_from(result);
372   bool oop_result_flag = is_reference_type(result->get_type());
373 
374   // Find receiver
375   Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
376 
377   // When we reenter Java, we need to reenable the reserved/yellow zone which
378   // might already be disabled when we are in VM.
379   thread->stack_overflow_state()->reguard_stack_if_needed();
380 
381   // Check that there are shadow pages available before changing thread state
382   // to Java. Calculate current_stack_pointer here to make sure
383   // stack_shadow_pages_available() and bang_stack_shadow_pages() use the same sp.
384   address sp = os::current_stack_pointer();
385   if (!os::stack_shadow_pages_available(THREAD, method, sp)) {
386     // Throw stack overflow exception with preinitialized exception.
387     Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
388     return;
389   } else {
390     // Touch pages checked if the OS needs them to be touched to be mapped.
391     os::map_stack_shadow_pages(sp);
392   }
393 
394   // do call
395   { JavaCallWrapper link(method, receiver, result, CHECK);
396     { HandleMark hm(thread);  // HandleMark used by HandleMarkCleaner
397 
398       // NOTE: if we move the computation of the result_val_address inside
399       // the call to call_stub, the optimizer produces wrong code.
400       intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
401       intptr_t* parameter_address = args->parameters();
402 #if INCLUDE_JVMCI
403       // Gets the alternative target (if any) that should be called
404       Handle alternative_target = args->alternative_target();
405       if (!alternative_target.is_null()) {
406         // Must extract verified entry point from HotSpotNmethod after VM to Java
407         // transition in JavaCallWrapper constructor so that it is safe with
408         // respect to nmethod sweeping.
409         address verified_entry_point = (address) HotSpotJVMCI::InstalledCode::entryPoint(NULL, alternative_target());
410         if (verified_entry_point != NULL) {
411           thread->set_jvmci_alternate_call_target(verified_entry_point);
412           entry_point = method->adapter()->get_i2c_entry();
413         }
414       }
415 #endif
416       StubRoutines::call_stub()(
417         (address)&link,
418         // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
419         result_val_address,          // see NOTE above (compiler problem)
420         result_type,
421         method(),
422         entry_point,
423         parameter_address,
424         args->size_of_parameters(),
425         CHECK
426       );
427 
428       result = link.result();  // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
429       // Preserve oop return value across possible gc points
430       if (oop_result_flag) {
431         thread->set_vm_result(result->get_oop());
432       }
433     }
434   } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
435 
436   // Check if a thread stop or suspend should be executed
437   // The following assert was not realistic.  Thread.stop can set that bit at any moment.
438   //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
439 
440   // Restore possible oop return
441   if (oop_result_flag) {
442     result->set_oop(thread->vm_result());
443     thread->set_vm_result(NULL);
444   }
445 }
446 
447 
448 //--------------------------------------------------------------------------------------
449 // Implementation of JavaCallArguments
450 
451 inline bool is_value_state_indirect_oop(uint state) {
452   assert(state != JavaCallArguments::value_state_oop,
453          "Checking for handles after removal");
454   assert(state < JavaCallArguments::value_state_limit,
455          "Invalid value state %u", state);
456   return state != JavaCallArguments::value_state_primitive;
457 }
458 
459 inline oop resolve_indirect_oop(intptr_t value, uint state) {
460   switch (state) {
461   case JavaCallArguments::value_state_handle:
462   {
463     oop* ptr = reinterpret_cast<oop*>(value);
464     return Handle::raw_resolve(ptr);
465   }
466 
467   case JavaCallArguments::value_state_jobject:
468   {
469     jobject obj = reinterpret_cast<jobject>(value);
470     return JNIHandles::resolve(obj);
471   }
472 
473   default:
474     ShouldNotReachHere();
475     return NULL;
476   }
477 }
478 
479 intptr_t* JavaCallArguments::parameters() {
480   // First convert all handles to oops
481   for(int i = 0; i < _size; i++) {
482     uint state = _value_state[i];
483     assert(state != value_state_oop, "Multiple handle conversions");
484     if (is_value_state_indirect_oop(state)) {
485       oop obj = resolve_indirect_oop(_value[i], state);
486       _value[i] = cast_from_oop<intptr_t>(obj);
487       _value_state[i] = value_state_oop;
488     }
489   }
490   // Return argument vector
491   return _value;
492 }
493 
494 
495 class SignatureChekker : public SignatureIterator {
496  private:
497    int _pos;
498    BasicType _return_type;
499    u_char* _value_state;
500    intptr_t* _value;
501 
502  public:
503   SignatureChekker(Symbol* signature,
504                    BasicType return_type,
505                    bool is_static,
506                    u_char* value_state,
507                    intptr_t* value) :
508     SignatureIterator(signature),
509     _pos(0),
510     _return_type(return_type),
511     _value_state(value_state),
512     _value(value)
513   {
514     if (!is_static) {
515       check_value(true); // Receiver must be an oop
516     }
517     do_parameters_on(this);
518     check_return_type(return_type);
519   }
520 
521  private:
522   void check_value(bool is_reference) {
523     uint state = _value_state[_pos++];
524     if (is_reference) {
525       guarantee(is_value_state_indirect_oop(state),
526                 "signature does not match pushed arguments: %u at %d",
527                 state, _pos - 1);
528     } else {
529       guarantee(state == JavaCallArguments::value_state_primitive,
530                 "signature does not match pushed arguments: %u at %d",
531                 state, _pos - 1);
532     }
533   }
534 
535   void check_return_type(BasicType t) {
536     guarantee(t == _return_type, "return type does not match");
537   }
538 
539   void check_single_word() {
540     check_value(false);
541   }
542 
543   void check_double_word() {
544     check_value(false);
545     check_value(false);
546   }
547 
548   void check_reference() {
549     intptr_t v = _value[_pos];
550     if (v != 0) {
551       // v is a "handle" referring to an oop, cast to integral type.
552       // There shouldn't be any handles in very low memory.
553       guarantee((size_t)v >= (size_t)os::vm_page_size(),
554                 "Bad JNI oop argument %d: " PTR_FORMAT, _pos, v);
555       // Verify the pointee.
556       oop vv = resolve_indirect_oop(v, _value_state[_pos]);
557       guarantee(oopDesc::is_oop_or_null(vv, true),
558                 "Bad JNI oop argument %d: " PTR_FORMAT " -> " PTR_FORMAT,
559                 _pos, v, p2i(vv));
560     }
561 
562     check_value(true);          // Verify value state.
563   }
564 
565   friend class SignatureIterator;  // so do_parameters_on can call do_type
566   void do_type(BasicType type) {
567     switch (type) {
568     case T_BYTE:
569     case T_BOOLEAN:
570     case T_CHAR:
571     case T_SHORT:
572     case T_INT:
573     case T_FLOAT:  // this one also
574       check_single_word(); break;
575     case T_LONG:
576     case T_DOUBLE:
577       check_double_word(); break;
578     case T_ARRAY:
579     case T_OBJECT:
580       check_reference(); break;
581     default:
582       ShouldNotReachHere();
583     }
584   }
585 };
586 
587 
588 void JavaCallArguments::verify(const methodHandle& method, BasicType return_type) {
589   guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
590 
591   // Treat T_OBJECT and T_ARRAY as the same
592   if (is_reference_type(return_type)) return_type = T_OBJECT;
593 
594   // Check that oop information is correct
595   Symbol* signature = method->signature();
596 
597   SignatureChekker sc(signature,
598                       return_type,
599                       method->is_static(),
600                       _value_state,
601                       _value);
602 }