1 /*
   2  * Copyright (c) 1998, 2014, 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 "compiler/compileBroker.hpp"
  29 #include "oops/oop.inline.hpp"
  30 #include "runtime/init.hpp"
  31 #include "runtime/java.hpp"
  32 #include "runtime/javaCalls.hpp"
  33 #include "runtime/thread.inline.hpp"
  34 #include "runtime/threadCritical.hpp"
  35 #include "utilities/events.hpp"
  36 #include "utilities/exceptions.hpp"
  37 
  38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  39 
  40 // Implementation of ThreadShadow
  41 void check_ThreadShadow() {
  42   const ByteSize offset1 = byte_offset_of(ThreadShadow, _pending_exception);
  43   const ByteSize offset2 = Thread::pending_exception_offset();
  44   if (offset1 != offset2) fatal("ThreadShadow::_pending_exception is not positioned correctly");
  45 }
  46 
  47 
  48 void ThreadShadow::set_pending_exception(oop exception, const char* file, int line) {
  49   assert(exception != NULL && exception->is_oop(), "invalid exception oop");
  50   _pending_exception = exception;
  51   _exception_file    = file;
  52   _exception_line    = line;
  53 }
  54 
  55 void ThreadShadow::clear_pending_exception() {
  56   if (TraceClearedExceptions) {
  57     if (_pending_exception != NULL) {
  58       tty->print_cr("Thread::clear_pending_exception: cleared exception:");
  59       _pending_exception->print();
  60     }
  61   }
  62   _pending_exception = NULL;
  63   _exception_file    = NULL;
  64   _exception_line    = 0;
  65 }
  66 // Implementation of Exceptions
  67 
  68 bool Exceptions::special_exception(Thread* thread, const char* file, int line, Handle h_exception) {
  69   // bootstrapping check
  70   if (!Universe::is_fully_initialized()) {
  71    vm_exit_during_initialization(h_exception);
  72    ShouldNotReachHere();
  73   }
  74 
  75 #ifdef ASSERT
  76   // Check for trying to throw stack overflow before initialization is complete
  77   // to prevent infinite recursion trying to initialize stack overflow without
  78   // adequate stack space.
  79   // This can happen with stress testing a large value of StackShadowPages
  80   if (h_exception()->klass() == SystemDictionary::StackOverflowError_klass()) {
  81     InstanceKlass* ik = InstanceKlass::cast(h_exception->klass());
  82     assert(ik->is_initialized(),
  83            "need to increase min_stack_allowed calculation");
  84   }
  85 #endif // ASSERT
  86 
  87   if (thread->is_VM_thread()
  88       || thread->is_Compiler_thread()
  89       || DumpSharedSpaces ) {
  90     // We do not care what kind of exception we get for the vm-thread or a thread which
  91     // is compiling.  We just install a dummy exception object
  92     //
  93     // We also cannot throw a proper exception when dumping, because we cannot run
  94     // Java bytecodes now. A dummy exception will suffice.
  95     thread->set_pending_exception(Universe::vm_exception(), file, line);
  96     return true;
  97   }
  98 
  99   return false;
 100 }
 101 
 102 bool Exceptions::special_exception(Thread* thread, const char* file, int line, Symbol* h_name, const char* message) {
 103   // bootstrapping check
 104   if (!Universe::is_fully_initialized()) {
 105     if (h_name == NULL) {
 106       // atleast an informative message.
 107       vm_exit_during_initialization("Exception", message);
 108     } else {
 109       vm_exit_during_initialization(h_name, message);
 110     }
 111     ShouldNotReachHere();
 112   }
 113 
 114   if (thread->is_VM_thread()
 115       || thread->is_Compiler_thread()
 116       || DumpSharedSpaces ) {
 117     // We do not care what kind of exception we get for the vm-thread or a thread which
 118     // is compiling.  We just install a dummy exception object
 119     //
 120     // We also cannot throw a proper exception when dumping, because we cannot run
 121     // Java bytecodes now. A dummy exception will suffice.
 122     thread->set_pending_exception(Universe::vm_exception(), file, line);
 123     return true;
 124   }
 125   return false;
 126 }
 127 
 128 // This method should only be called from generated code,
 129 // therefore the exception oop should be in the oopmap.
 130 void Exceptions::_throw_oop(Thread* thread, const char* file, int line, oop exception) {
 131   assert(exception != NULL, "exception should not be NULL");
 132   Handle h_exception = Handle(thread, exception);
 133   _throw(thread, file, line, h_exception);
 134 }
 135 
 136 void Exceptions::_throw(Thread* thread, const char* file, int line, Handle h_exception, const char* message) {
 137   ResourceMark rm;
 138   assert(h_exception() != NULL, "exception should not be NULL");
 139 
 140   // tracing (do this up front - so it works during boot strapping)
 141   if (TraceExceptions) {
 142     ttyLocker ttyl;
 143     tty->print_cr("Exception <%s%s%s> (" INTPTR_FORMAT ") \n"
 144                   "thrown [%s, line %d]\nfor thread " INTPTR_FORMAT,
 145                   h_exception->print_value_string(),
 146                   message ? ": " : "", message ? message : "",
 147                   (address)h_exception(), file, line, thread);
 148   }
 149   // for AbortVMOnException flag
 150   NOT_PRODUCT(Exceptions::debug_check_abort(h_exception, message));
 151 
 152   // Check for special boot-strapping/vm-thread handling
 153   if (special_exception(thread, file, line, h_exception)) {
 154     return;
 155   }
 156 
 157   assert(h_exception->is_a(SystemDictionary::Throwable_klass()), "exception is not a subclass of java/lang/Throwable");
 158 
 159   // set the pending exception
 160   thread->set_pending_exception(h_exception(), file, line);
 161 
 162   // vm log
 163   Events::log_exception(thread, "Exception <%s%s%s> (" INTPTR_FORMAT ") thrown at [%s, line %d]",
 164                         h_exception->print_value_string(), message ? ": " : "", message ? message : "",
 165                         (address)h_exception(), file, line);
 166 }
 167 
 168 
 169 void Exceptions::_throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message,
 170                             Handle h_loader, Handle h_protection_domain) {
 171   // Check for special boot-strapping/vm-thread handling
 172   if (special_exception(thread, file, line, name, message)) return;
 173   // Create and throw exception
 174   Handle h_cause(thread, NULL);
 175   Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);
 176   _throw(thread, file, line, h_exception, message);
 177 }
 178 
 179 void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
 180                                   Handle h_loader, Handle h_protection_domain) {
 181   // Check for special boot-strapping/vm-thread handling
 182   if (special_exception(thread, file, line, name, message)) return;
 183   // Create and throw exception and init cause
 184   Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);
 185   _throw(thread, file, line, h_exception, message);
 186 }
 187 
 188 void Exceptions::_throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause,
 189                               Handle h_loader, Handle h_protection_domain) {
 190   // Check for special boot-strapping/vm-thread handling
 191   if (special_exception(thread, file, line, h_cause)) return;
 192   // Create and throw exception
 193   Handle h_exception = new_exception(thread, name, h_cause, h_loader, h_protection_domain);
 194   _throw(thread, file, line, h_exception, NULL);
 195 }
 196 
 197 void Exceptions::_throw_args(Thread* thread, const char* file, int line, Symbol* name, Symbol* signature, JavaCallArguments *args) {
 198   // Check for special boot-strapping/vm-thread handling
 199   if (special_exception(thread, file, line, name, NULL)) return;
 200   // Create and throw exception
 201   Handle h_loader(thread, NULL);
 202   Handle h_prot(thread, NULL);
 203   Handle exception = new_exception(thread, name, signature, args, h_loader, h_prot);
 204   _throw(thread, file, line, exception);
 205 }
 206 
 207 
 208 // Methods for default parameters.
 209 // NOTE: These must be here (and not in the header file) because of include circularities.
 210 void Exceptions::_throw_msg_cause(Thread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause) {
 211   _throw_msg_cause(thread, file, line, name, message, h_cause, Handle(thread, NULL), Handle(thread, NULL));
 212 }
 213 void Exceptions::_throw_msg(Thread* thread, const char* file, int line, Symbol* name, const char* message) {
 214   _throw_msg(thread, file, line, name, message, Handle(thread, NULL), Handle(thread, NULL));
 215 }
 216 void Exceptions::_throw_cause(Thread* thread, const char* file, int line, Symbol* name, Handle h_cause) {
 217   _throw_cause(thread, file, line, name, h_cause, Handle(thread, NULL), Handle(thread, NULL));
 218 }
 219 
 220 
 221 void Exceptions::throw_stack_overflow_exception(Thread* THREAD, const char* file, int line, methodHandle method) {
 222   Handle exception;
 223   if (!THREAD->has_pending_exception()) {
 224     Klass* k = SystemDictionary::StackOverflowError_klass();
 225     oop e = InstanceKlass::cast(k)->allocate_instance(CHECK);
 226     exception = Handle(THREAD, e);  // fill_in_stack trace does gc
 227     assert(InstanceKlass::cast(k)->is_initialized(), "need to increase min_stack_allowed calculation");
 228     if (StackTraceInThrowable) {
 229       java_lang_Throwable::fill_in_stack_trace(exception, method());
 230     }
 231   } else {
 232     // if prior exception, throw that one instead
 233     exception = Handle(THREAD, THREAD->pending_exception());
 234   }
 235   _throw(THREAD, file, line, exception);
 236 }
 237 
 238 void Exceptions::fthrow(Thread* thread, const char* file, int line, Symbol* h_name, const char* format, ...) {
 239   const int max_msg_size = 1024;
 240   va_list ap;
 241   va_start(ap, format);
 242   char msg[max_msg_size];
 243   vsnprintf(msg, max_msg_size, format, ap);
 244   msg[max_msg_size-1] = '\0';
 245   va_end(ap);
 246   _throw_msg(thread, file, line, h_name, msg);
 247 }
 248 
 249 
 250 // Creates an exception oop, calls the <init> method with the given signature.
 251 // and returns a Handle
 252 Handle Exceptions::new_exception(Thread *thread, Symbol* name,
 253                                  Symbol* signature, JavaCallArguments *args,
 254                                  Handle h_loader, Handle h_protection_domain) {
 255   assert(Universe::is_fully_initialized(),
 256     "cannot be called during initialization");
 257   assert(thread->is_Java_thread(), "can only be called by a Java thread");
 258   assert(!thread->has_pending_exception(), "already has exception");
 259 
 260   Handle h_exception;
 261 
 262   // Resolve exception klass
 263   Klass* ik = SystemDictionary::resolve_or_fail(name, h_loader, h_protection_domain, true, thread);
 264   instanceKlassHandle klass(thread, ik);
 265 
 266   if (!thread->has_pending_exception()) {
 267     assert(klass.not_null(), "klass must exist");
 268     // We are about to create an instance - so make sure that klass is initialized
 269     klass->initialize(thread);
 270     if (!thread->has_pending_exception()) {
 271       // Allocate new exception
 272       h_exception = klass->allocate_instance_handle(thread);
 273       if (!thread->has_pending_exception()) {
 274         JavaValue result(T_VOID);
 275         args->set_receiver(h_exception);
 276         // Call constructor
 277         JavaCalls::call_special(&result, klass,
 278                                          vmSymbols::object_initializer_name(),
 279                                          signature,
 280                                          args,
 281                                          thread);
 282       }
 283     }
 284   }
 285 
 286   // Check if another exception was thrown in the process, if so rethrow that one
 287   if (thread->has_pending_exception()) {
 288     h_exception = Handle(thread, thread->pending_exception());
 289     thread->clear_pending_exception();
 290   }
 291   return h_exception;
 292 }
 293 
 294 // Creates an exception oop, calls the <init> method with the given signature.
 295 // and returns a Handle
 296 // Initializes the cause if cause non-null
 297 Handle Exceptions::new_exception(Thread *thread, Symbol* name,
 298                                  Symbol* signature, JavaCallArguments *args,
 299                                  Handle h_cause,
 300                                  Handle h_loader, Handle h_protection_domain) {
 301   Handle h_exception = new_exception(thread, name, signature, args, h_loader, h_protection_domain);
 302 
 303   // Future: object initializer should take a cause argument
 304   if (h_cause.not_null()) {
 305     assert(h_cause->is_a(SystemDictionary::Throwable_klass()),
 306         "exception cause is not a subclass of java/lang/Throwable");
 307     JavaValue result1(T_OBJECT);
 308     JavaCallArguments args1;
 309     args1.set_receiver(h_exception);
 310     args1.push_oop(h_cause);
 311     JavaCalls::call_virtual(&result1, h_exception->klass(),
 312                                       vmSymbols::initCause_name(),
 313                                       vmSymbols::throwable_throwable_signature(),
 314                                       &args1,
 315                                       thread);
 316   }
 317 
 318   // Check if another exception was thrown in the process, if so rethrow that one
 319   if (thread->has_pending_exception()) {
 320     h_exception = Handle(thread, thread->pending_exception());
 321     thread->clear_pending_exception();
 322   }
 323   return h_exception;
 324 }
 325 
 326 // Convenience method. Calls either the <init>() or <init>(Throwable) method when
 327 // creating a new exception
 328 Handle Exceptions::new_exception(Thread* thread, Symbol* name,
 329                                  Handle h_cause,
 330                                  Handle h_loader, Handle h_protection_domain,
 331                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
 332   JavaCallArguments args;
 333   Symbol* signature = NULL;
 334   if (h_cause.is_null()) {
 335     signature = vmSymbols::void_method_signature();
 336   } else {
 337     signature = vmSymbols::throwable_void_signature();
 338     args.push_oop(h_cause);
 339   }
 340   return new_exception(thread, name, signature, &args, h_loader, h_protection_domain);
 341 }
 342 
 343 // Convenience method. Calls either the <init>() or <init>(String) method when
 344 // creating a new exception
 345 Handle Exceptions::new_exception(Thread* thread, Symbol* name,
 346                                  const char* message, Handle h_cause,
 347                                  Handle h_loader, Handle h_protection_domain,
 348                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
 349   JavaCallArguments args;
 350   Symbol* signature = NULL;
 351   if (message == NULL) {
 352     signature = vmSymbols::void_method_signature();
 353   } else {
 354     // We want to allocate storage, but we can't do that if there's
 355     // a pending exception, so we preserve any pending exception
 356     // around the allocation.
 357     // If we get an exception from the allocation, prefer that to
 358     // the exception we are trying to build, or the pending exception.
 359     // This is sort of like what PRESERVE_EXCEPTION_MARK does, except
 360     // for the preferencing and the early returns.
 361     Handle incoming_exception(thread, NULL);
 362     if (thread->has_pending_exception()) {
 363       incoming_exception = Handle(thread, thread->pending_exception());
 364       thread->clear_pending_exception();
 365     }
 366     Handle msg;
 367     if (to_utf8_safe == safe_to_utf8) {
 368       // Make a java UTF8 string.
 369       msg = java_lang_String::create_from_str(message, thread);
 370     } else {
 371       // Make a java string keeping the encoding scheme of the original string.
 372       msg = java_lang_String::create_from_platform_dependent_str(message, thread);
 373     }
 374     if (thread->has_pending_exception()) {
 375       Handle exception(thread, thread->pending_exception());
 376       thread->clear_pending_exception();
 377       return exception;
 378     }
 379     if (incoming_exception.not_null()) {
 380       return incoming_exception;
 381     }
 382     args.push_oop(msg);
 383     signature = vmSymbols::string_void_signature();
 384   }
 385   return new_exception(thread, name, signature, &args, h_cause, h_loader, h_protection_domain);
 386 }
 387 
 388 // Another convenience method that creates handles for null class loaders and
 389 // protection domains and null causes.
 390 // If the last parameter 'to_utf8_mode' is safe_to_utf8,
 391 // it means we can safely ignore the encoding scheme of the message string and
 392 // convert it directly to a java UTF8 string. Otherwise, we need to take the
 393 // encoding scheme of the string into account. One thing we should do at some
 394 // point is to push this flag down to class java_lang_String since other
 395 // classes may need similar functionalities.
 396 Handle Exceptions::new_exception(Thread* thread, Symbol* name,
 397                                  const char* message,
 398                                  ExceptionMsgToUtf8Mode to_utf8_safe) {
 399 
 400   Handle       h_loader(thread, NULL);
 401   Handle       h_prot(thread, NULL);
 402   Handle       h_cause(thread, NULL);
 403   return Exceptions::new_exception(thread, name, message, h_cause, h_loader,
 404                                    h_prot, to_utf8_safe);
 405 }
 406 
 407 // Implementation of ExceptionMark
 408 
 409 ExceptionMark::ExceptionMark(Thread*& thread) {
 410   thread     = Thread::current();
 411   _thread    = thread;
 412   if (_thread->has_pending_exception()) {
 413     oop exception = _thread->pending_exception();
 414     _thread->clear_pending_exception(); // Needed to avoid infinite recursion
 415     exception->print();
 416     fatal("ExceptionMark constructor expects no pending exceptions");
 417   }
 418 }
 419 
 420 
 421 ExceptionMark::~ExceptionMark() {
 422   if (_thread->has_pending_exception()) {
 423     Handle exception(_thread, _thread->pending_exception());
 424     _thread->clear_pending_exception(); // Needed to avoid infinite recursion
 425     if (is_init_completed()) {
 426       exception->print();
 427       fatal("ExceptionMark destructor expects no pending exceptions");
 428     } else {
 429       vm_exit_during_initialization(exception);
 430     }
 431   }
 432 }
 433 
 434 // ----------------------------------------------------------------------------------------
 435 
 436 #ifndef PRODUCT
 437 // caller frees value_string if necessary
 438 void Exceptions::debug_check_abort(const char *value_string, const char* message) {
 439   if (AbortVMOnException != NULL && value_string != NULL &&
 440       strstr(value_string, AbortVMOnException)) {
 441     if (AbortVMOnExceptionMessage == NULL || message == NULL ||
 442         strcmp(message, AbortVMOnExceptionMessage) == 0) {
 443       fatal(err_msg("Saw %s, aborting", value_string));
 444     }
 445   }
 446 }
 447 
 448 void Exceptions::debug_check_abort(Handle exception, const char* message) {
 449   if (AbortVMOnException != NULL) {
 450     ResourceMark rm;
 451     if (message == NULL && exception->is_a(SystemDictionary::Throwable_klass())) {
 452       oop msg = java_lang_Throwable::message(exception);
 453       if (msg != NULL) {
 454         message = java_lang_String::as_utf8_string(msg);
 455       }
 456     }
 457     debug_check_abort(InstanceKlass::cast(exception()->klass())->external_name(), message);
 458   }
 459 }
 460 #endif