1 /*
   2  * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "classfile/vmSymbols.hpp"
  28 #include "code/nmethod.hpp"
  29 #include "compiler/compileBroker.hpp"
  30 #include "interpreter/interpreter.hpp"
  31 #include "interpreter/linkResolver.hpp"
  32 #include "memory/universe.inline.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "prims/jniCheck.hpp"
  35 #include "runtime/compilationPolicy.hpp"
  36 #include "runtime/handles.inline.hpp"
  37 #include "runtime/interfaceSupport.hpp"
  38 #include "runtime/javaCalls.hpp"
  39 #include "runtime/mutexLocker.hpp"
  40 #include "runtime/signature.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "runtime/thread.inline.hpp"
  43 
  44 // -----------------------------------------------------
  45 // Implementation of JavaCallWrapper
  46 
  47 JavaCallWrapper::JavaCallWrapper(methodHandle callee_method, Handle receiver, JavaValue* result, TRAPS) {
  48   JavaThread* thread = (JavaThread *)THREAD;
  49   bool clear_pending_exception = true;
  50 
  51   guarantee(thread->is_Java_thread(), "crucial check - the VM thread cannot and must not escape to Java code");
  52   assert(!thread->owns_locks(), "must release all locks when leaving VM");
  53   guarantee(!thread->is_Compiler_thread(), "cannot make java calls from the compiler");
  54   _result   = result;
  55 
  56   // Allocate handle block for Java code. This must be done before we change thread_state to _thread_in_Java_or_stub,
  57   // since it can potentially block.
  58   JNIHandleBlock* new_handles = JNIHandleBlock::allocate_block(thread);
  59 
  60   // After this, we are official in JavaCode. This needs to be done before we change any of the thread local
  61   // info, since we cannot find oops before the new information is set up completely.
  62   ThreadStateTransition::transition(thread, _thread_in_vm, _thread_in_Java);
  63 
  64   // Make sure that we handle asynchronous stops and suspends _before_ we clear all thread state
  65   // in JavaCallWrapper::JavaCallWrapper(). This way, we can decide if we need to do any pd actions
  66   // to prepare for stop/suspend (flush register windows on sparcs, cache sp, or other state).
  67   if (thread->has_special_runtime_exit_condition()) {
  68     thread->handle_special_runtime_exit_condition();
  69     if (HAS_PENDING_EXCEPTION) {
  70       clear_pending_exception = false;
  71     }
  72   }
  73 
  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       = (JavaThread *)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 == NULL 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   assert (_thread->thread_state() != _thread_in_native, "cannot set native pc to NULL");
  99 
 100   // clear any pending exception in thread (native calls start with no exception pending)
 101   if(clear_pending_exception) {
 102     _thread->clear_pending_exception();
 103   }
 104 
 105   if (_anchor.last_Java_sp() == NULL) {
 106     _thread->record_base_of_stack_pointer();
 107   }
 108 }
 109 
 110 
 111 JavaCallWrapper::~JavaCallWrapper() {
 112   assert(_thread == JavaThread::current(), "must still be the same thread");
 113 
 114   // restore previous handle block & Java frame linkage
 115   JNIHandleBlock *_old_handles = _thread->active_handles();
 116   _thread->set_active_handles(_handles);
 117 
 118   _thread->frame_anchor()->zap();
 119 
 120   debug_only(_thread->dec_java_call_counter());
 121 
 122   if (_anchor.last_Java_sp() == NULL) {
 123     _thread->set_base_of_stack_pointer(NULL);
 124   }
 125 
 126 
 127   // Old thread-local info. has been restored. We are not back in the VM.
 128   ThreadStateTransition::transition_from_java(_thread, _thread_in_vm);
 129 
 130   // State has been restored now make the anchor frame visible for the profiler.
 131   // Do this after the transition because this allows us to put an assert
 132   // the Java->vm transition which checks to see that stack is not walkable
 133   // on sparc/ia64 which will catch violations of the reseting of last_Java_frame
 134   // invariants (i.e. _flags always cleared on return to Java)
 135 
 136   _thread->frame_anchor()->copy(&_anchor);
 137 
 138   // Release handles after we are marked as being inside the VM again, since this
 139   // operation might block
 140   JNIHandleBlock::release_block(_old_handles, _thread);
 141 }
 142 
 143 
 144 void JavaCallWrapper::oops_do(OopClosure* f) {
 145   f->do_oop((oop*)&_receiver);
 146   handles()->oops_do(f);
 147 }
 148 
 149 
 150 // Helper methods
 151 static BasicType runtime_type_from(JavaValue* result) {
 152   switch (result->get_type()) {
 153     case T_BOOLEAN: // fall through
 154     case T_CHAR   : // fall through
 155     case T_SHORT  : // fall through
 156     case T_INT    : // fall through
 157 #ifndef _LP64
 158     case T_OBJECT : // fall through
 159     case T_ARRAY  : // fall through
 160 #endif
 161     case T_BYTE   : // fall through
 162     case T_VOID   : return T_INT;
 163     case T_LONG   : return T_LONG;
 164     case T_FLOAT  : return T_FLOAT;
 165     case T_DOUBLE : return T_DOUBLE;
 166 #ifdef _LP64
 167     case T_ARRAY  : // fall through
 168     case T_OBJECT:  return T_OBJECT;
 169 #endif
 170   }
 171   ShouldNotReachHere();
 172   return T_ILLEGAL;
 173 }
 174 
 175 // ===== object constructor calls =====
 176 
 177 void JavaCalls::call_default_constructor(JavaThread* thread, methodHandle method, Handle receiver, TRAPS) {
 178   assert(method->name() == vmSymbols::object_initializer_name(),    "Should only be called for default constructor");
 179   assert(method->signature() == vmSymbols::void_method_signature(), "Should only be called for default constructor");
 180 
 181   InstanceKlass* ik = method->method_holder();
 182   if (ik->is_initialized() && ik->has_vanilla_constructor()) {
 183     // safe to skip constructor call
 184   } else {
 185     static JavaValue result(T_VOID);
 186     JavaCallArguments args(receiver);
 187     call(&result, method, &args, CHECK);
 188   }
 189 }
 190 
 191 // ============ Virtual calls ============
 192 
 193 void JavaCalls::call_virtual(JavaValue* result, KlassHandle spec_klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 194   CallInfo callinfo;
 195   Handle receiver = args->receiver();
 196   KlassHandle recvrKlass(THREAD, receiver.is_null() ? (Klass*)NULL : receiver->klass());
 197   LinkResolver::resolve_virtual_call(
 198           callinfo, receiver, recvrKlass, spec_klass, name, signature,
 199           KlassHandle(), false, true, CHECK);
 200   methodHandle method = callinfo.selected_method();
 201   assert(method.not_null(), "should have thrown exception");
 202 
 203   // Invoke the method
 204   JavaCalls::call(result, method, args, CHECK);
 205 }
 206 
 207 
 208 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, TRAPS) {
 209   JavaCallArguments args(receiver); // One oop argument
 210   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 211 }
 212 
 213 
 214 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 215   JavaCallArguments args(receiver); // One oop argument
 216   args.push_oop(arg1);
 217   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 218 }
 219 
 220 
 221 
 222 void JavaCalls::call_virtual(JavaValue* result, Handle receiver, KlassHandle spec_klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 223   JavaCallArguments args(receiver); // One oop argument
 224   args.push_oop(arg1);
 225   args.push_oop(arg2);
 226   call_virtual(result, spec_klass, name, signature, &args, CHECK);
 227 }
 228 
 229 
 230 // ============ Special calls ============
 231 
 232 void JavaCalls::call_special(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 233   CallInfo callinfo;
 234   LinkResolver::resolve_special_call(callinfo, args->receiver(), klass, name, signature, KlassHandle(), false, CHECK);
 235   methodHandle method = callinfo.selected_method();
 236   assert(method.not_null(), "should have thrown exception");
 237 
 238   // Invoke the method
 239   JavaCalls::call(result, method, args, CHECK);
 240 }
 241 
 242 
 243 void JavaCalls::call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS) {
 244   JavaCallArguments args(receiver); // One oop argument
 245   call_special(result, klass, name, signature, &args, CHECK);
 246 }
 247 
 248 
 249 void JavaCalls::call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 250   JavaCallArguments args(receiver); // One oop argument
 251   args.push_oop(arg1);
 252   call_special(result, klass, name, signature, &args, CHECK);
 253 }
 254 
 255 
 256 void JavaCalls::call_special(JavaValue* result, Handle receiver, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 257   JavaCallArguments args(receiver); // One oop argument
 258   args.push_oop(arg1);
 259   args.push_oop(arg2);
 260   call_special(result, klass, name, signature, &args, CHECK);
 261 }
 262 
 263 
 264 // ============ Static calls ============
 265 
 266 void JavaCalls::call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, JavaCallArguments* args, TRAPS) {
 267   CallInfo callinfo;
 268   LinkResolver::resolve_static_call(callinfo, klass, name, signature, KlassHandle(), false, true, CHECK);
 269   methodHandle method = callinfo.selected_method();
 270   assert(method.not_null(), "should have thrown exception");
 271 
 272   // Invoke the method
 273   JavaCalls::call(result, method, args, CHECK);
 274 }
 275 
 276 
 277 void JavaCalls::call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, TRAPS) {
 278   JavaCallArguments args; // No argument
 279   call_static(result, klass, name, signature, &args, CHECK);
 280 }
 281 
 282 
 283 void JavaCalls::call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, TRAPS) {
 284   JavaCallArguments args(arg1); // One oop argument
 285   call_static(result, klass, name, signature, &args, CHECK);
 286 }
 287 
 288 
 289 void JavaCalls::call_static(JavaValue* result, KlassHandle klass, Symbol* name, Symbol* signature, Handle arg1, Handle arg2, TRAPS) {
 290   JavaCallArguments args; // One oop argument
 291   args.push_oop(arg1);
 292   args.push_oop(arg2);
 293   call_static(result, klass, name, signature, &args, CHECK);
 294 }
 295 
 296 
 297 // -------------------------------------------------
 298 // Implementation of JavaCalls (low level)
 299 
 300 
 301 void JavaCalls::call(JavaValue* result, methodHandle method, JavaCallArguments* args, TRAPS) {
 302   // Check if we need to wrap a potential OS exception handler around thread
 303   // This is used for e.g. Win32 structured exception handlers
 304   assert(THREAD->is_Java_thread(), "only JavaThreads can make JavaCalls");
 305   // Need to wrap each and everytime, since there might be native code down the
 306   // stack that has installed its own exception handlers
 307   os::os_exception_wrapper(call_helper, result, &method, args, THREAD);
 308 }
 309 
 310 void JavaCalls::call_helper(JavaValue* result, methodHandle* m, JavaCallArguments* args, TRAPS) {
 311   // During dumping, Java execution environment is not fully initialized. Also, Java execution
 312   // may cause undesirable side-effects in the class metadata.
 313   assert(!DumpSharedSpaces, "must not execute Java bytecodes when dumping");
 314 
 315   methodHandle method = *m;
 316   JavaThread* thread = (JavaThread*)THREAD;
 317   assert(thread->is_Java_thread(), "must be called by a java thread");
 318   assert(method.not_null(), "must have a method to call");
 319   assert(!SafepointSynchronize::is_at_safepoint(), "call to Java code during VM operation");
 320   assert(!thread->handle_area()->no_handle_mark_active(), "cannot call out to Java here");
 321 
 322 
 323   CHECK_UNHANDLED_OOPS_ONLY(thread->clear_unhandled_oops();)
 324 
 325   // Verify the arguments
 326 
 327   if (CheckJNICalls)  {
 328     args->verify(method, result->get_type(), thread);
 329   }
 330   else debug_only(args->verify(method, result->get_type(), thread));
 331 
 332   // Ignore call if method is empty
 333   if (method->is_empty_method()) {
 334     assert(result->get_type() == T_VOID, "an empty method must return a void value");
 335     return;
 336   }
 337 
 338 
 339 #ifdef ASSERT
 340   { InstanceKlass* holder = method->method_holder();
 341     // A klass might not be initialized since JavaCall's might be used during the executing of
 342     // the <clinit>. For example, a Thread.start might start executing on an object that is
 343     // not fully initialized! (bad Java programming style)
 344     assert(holder->is_linked(), "rewritting must have taken place");
 345   }
 346 #endif
 347 
 348 
 349   assert(!thread->is_Compiler_thread(), "cannot compile from the compiler");
 350   if (CompilationPolicy::must_be_compiled(method)) {
 351     CompileBroker::compile_method(method, InvocationEntryBci,
 352                                   CompilationPolicy::policy()->initial_compile_level(),
 353                                   methodHandle(), 0, "must_be_compiled", CHECK);
 354   }
 355 
 356   // Since the call stub sets up like the interpreter we call the from_interpreted_entry
 357   // so we can go compiled via a i2c. Otherwise initial entry method will always
 358   // run interpreted.
 359   address entry_point = method->from_interpreted_entry();
 360   if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
 361     entry_point = method->interpreter_entry();
 362   }
 363 
 364   // Figure out if the result value is an oop or not (Note: This is a different value
 365   // than result_type. result_type will be T_INT of oops. (it is about size)
 366   BasicType result_type = runtime_type_from(result);
 367   bool oop_result_flag = (result->get_type() == T_OBJECT || result->get_type() == T_ARRAY);
 368 
 369   // NOTE: if we move the computation of the result_val_address inside
 370   // the call to call_stub, the optimizer produces wrong code.
 371   intptr_t* result_val_address = (intptr_t*)(result->get_value_addr());
 372 
 373   // Find receiver
 374   Handle receiver = (!method->is_static()) ? args->receiver() : Handle();
 375 
 376   // When we reenter Java, we need to reenable the yellow zone which
 377   // might already be disabled when we are in VM.
 378   if (thread->stack_yellow_zone_disabled()) {
 379     thread->reguard_stack();
 380   }
 381 
 382   // Check that there are shadow pages available before changing thread state
 383   // to Java
 384   if (!os::stack_shadow_pages_available(THREAD, method)) {
 385     // Throw stack overflow exception with preinitialized exception.
 386     Exceptions::throw_stack_overflow_exception(THREAD, __FILE__, __LINE__, method);
 387     return;
 388   } else {
 389     // Touch pages checked if the OS needs them to be touched to be mapped.
 390     os::bang_stack_shadow_pages();
 391   }
 392 
 393   // do call
 394   { JavaCallWrapper link(method, receiver, result, CHECK);
 395     { HandleMark hm(thread);  // HandleMark used by HandleMarkCleaner
 396 
 397       StubRoutines::call_stub()(
 398         (address)&link,
 399         // (intptr_t*)&(result->_value), // see NOTE above (compiler problem)
 400         result_val_address,          // see NOTE above (compiler problem)
 401         result_type,
 402         method(),
 403         entry_point,
 404         args->parameters(),
 405         args->size_of_parameters(),
 406         CHECK
 407       );
 408 
 409       result = link.result();  // circumvent MS C++ 5.0 compiler bug (result is clobbered across call)
 410       // Preserve oop return value across possible gc points
 411       if (oop_result_flag) {
 412         thread->set_vm_result((oop) result->get_jobject());
 413       }
 414     }
 415   } // Exit JavaCallWrapper (can block - potential return oop must be preserved)
 416 
 417   // Check if a thread stop or suspend should be executed
 418   // The following assert was not realistic.  Thread.stop can set that bit at any moment.
 419   //assert(!thread->has_special_runtime_exit_condition(), "no async. exceptions should be installed");
 420 
 421   // Restore possible oop return
 422   if (oop_result_flag) {
 423     result->set_jobject((jobject)thread->vm_result());
 424     thread->set_vm_result(NULL);
 425   }
 426 }
 427 
 428 
 429 //--------------------------------------------------------------------------------------
 430 // Implementation of JavaCallArguments
 431 
 432 intptr_t* JavaCallArguments::parameters() {
 433   // First convert all handles to oops
 434   for(int i = 0; i < _size; i++) {
 435     if (_is_oop[i]) {
 436       // Handle conversion
 437       _value[i] = cast_from_oop<intptr_t>(Handle::raw_resolve((oop *)_value[i]));
 438     }
 439   }
 440   // Return argument vector
 441   return _value;
 442 }
 443 
 444 
 445 class SignatureChekker : public SignatureIterator {
 446  private:
 447    bool *_is_oop;
 448    int   _pos;
 449    BasicType _return_type;
 450    intptr_t*   _value;
 451    Thread* _thread;
 452 
 453  public:
 454   bool _is_return;
 455 
 456   SignatureChekker(Symbol* signature, BasicType return_type, bool is_static, bool* is_oop, intptr_t* value, Thread* thread) : SignatureIterator(signature) {
 457     _is_oop = is_oop;
 458     _is_return = false;
 459     _return_type = return_type;
 460     _pos = 0;
 461     _value = value;
 462     _thread = thread;
 463 
 464     if (!is_static) {
 465       check_value(true); // Receiver must be an oop
 466     }
 467   }
 468 
 469   void check_value(bool type) {
 470     guarantee(_is_oop[_pos++] == type, "signature does not match pushed arguments");
 471   }
 472 
 473   void check_doing_return(bool state) { _is_return = state; }
 474 
 475   void check_return_type(BasicType t) {
 476     guarantee(_is_return && t == _return_type, "return type does not match");
 477   }
 478 
 479   void check_int(BasicType t) {
 480     if (_is_return) {
 481       check_return_type(t);
 482       return;
 483     }
 484     check_value(false);
 485   }
 486 
 487   void check_double(BasicType t) { check_long(t); }
 488 
 489   void check_long(BasicType t) {
 490     if (_is_return) {
 491       check_return_type(t);
 492       return;
 493     }
 494 
 495     check_value(false);
 496     check_value(false);
 497   }
 498 
 499   void check_obj(BasicType t) {
 500     if (_is_return) {
 501       check_return_type(t);
 502       return;
 503     }
 504 
 505     // verify handle and the oop pointed to by handle
 506     int p = _pos;
 507     bool bad = false;
 508     // If argument is oop
 509     if (_is_oop[p]) {
 510       intptr_t v = _value[p];
 511       if (v != 0 ) {
 512         size_t t = (size_t)v;
 513         bad = (t < (size_t)os::vm_page_size() ) || !Handle::raw_resolve((oop *)v)->is_oop_or_null(true);
 514         if (CheckJNICalls && bad) {
 515           ReportJNIFatalError((JavaThread*)_thread, "Bad JNI oop argument");
 516         }
 517       }
 518       // for the regular debug case.
 519       assert(!bad, "Bad JNI oop argument");
 520     }
 521 
 522     check_value(true);
 523   }
 524 
 525   void do_bool()                       { check_int(T_BOOLEAN);       }
 526   void do_char()                       { check_int(T_CHAR);          }
 527   void do_float()                      { check_int(T_FLOAT);         }
 528   void do_double()                     { check_double(T_DOUBLE);     }
 529   void do_byte()                       { check_int(T_BYTE);          }
 530   void do_short()                      { check_int(T_SHORT);         }
 531   void do_int()                        { check_int(T_INT);           }
 532   void do_long()                       { check_long(T_LONG);         }
 533   void do_void()                       { check_return_type(T_VOID);  }
 534   void do_object(int begin, int end)   { check_obj(T_OBJECT);        }
 535   void do_array(int begin, int end)    { check_obj(T_OBJECT);        }
 536 };
 537 
 538 
 539 void JavaCallArguments::verify(methodHandle method, BasicType return_type,
 540   Thread *thread) {
 541   guarantee(method->size_of_parameters() == size_of_parameters(), "wrong no. of arguments pushed");
 542 
 543   // Treat T_OBJECT and T_ARRAY as the same
 544   if (return_type == T_ARRAY) return_type = T_OBJECT;
 545 
 546   // Check that oop information is correct
 547   Symbol* signature = method->signature();
 548 
 549   SignatureChekker sc(signature, return_type, method->is_static(),_is_oop, _value, thread);
 550   sc.iterate_parameters();
 551   sc.check_doing_return(true);
 552   sc.iterate_returntype();
 553 }