exceptions.cpp

/*
 * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
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#include "precompiled.hpp"
#include "classfile/javaClasses.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmClasses.hpp"
#include "classfile/vmSymbols.hpp"
#include "compiler/compileBroker.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/init.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/os.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/threadCritical.hpp"
#include "runtime/atomic.hpp"
#include "utilities/events.hpp"
#include "utilities/exceptions.hpp"

// Implementation of ThreadShadow
void check_ThreadShadow() {
  const ByteSize offset1 = byte_offset_of(ThreadShadow, _pending_exception);
  const ByteSize offset2 = Thread::pending_exception_offset();
  if (offset1 != offset2) fatal("ThreadShadow::_pending_exception is not positioned correctly");
}


void ThreadShadow::set_pending_exception(oop exception, const char* file, int line) {
  assert(exception != NULL && oopDesc::is_oop(exception), "invalid exception oop");
  _pending_exception = exception;
  _exception_file    = file;
  _exception_line    = line;
}

void ThreadShadow::clear_pending_exception() {
  LogTarget(Debug, exceptions) lt;
  if (_pending_exception != NULL && lt.is_enabled()) {
    ResourceMark rm;
    LogStream ls(lt);
    ls.print("Thread::clear_pending_exception: cleared exception:");
    _pending_exception->print_on(&ls);
  }
  _pending_exception = NULL;
  _exception_file    = NULL;
  _exception_line    = 0;
}

void ThreadShadow::clear_pending_nonasync_exception() {
  // Do not clear probable async exceptions.
  if (!_pending_exception->is_a(vmClasses::ThreadDeath_klass()) &&
      (_pending_exception->klass() != vmClasses::InternalError_klass() ||
       java_lang_InternalError::during_unsafe_access(_pending_exception) != JNI_TRUE)) {
    clear_pending_exception();
  }
}

// Implementation of Exceptions

bool Exceptions::special_exception(JavaThread* thread, const char* file, int line, Handle h_exception) {
  // bootstrapping check
  if (!Universe::is_fully_initialized()) {
   vm_exit_during_initialization(h_exception);
   ShouldNotReachHere();
  }

#ifdef ASSERT
  // Check for trying to throw stack overflow before initialization is complete
  // to prevent infinite recursion trying to initialize stack overflow without
  // adequate stack space.
  // This can happen with stress testing a large value of StackShadowPages
  if (h_exception()->klass() == vmClasses::StackOverflowError_klass()) {
    InstanceKlass* ik = InstanceKlass::cast(h_exception->klass());
    assert(ik->is_initialized(),
           "need to increase java_thread_min_stack_allowed calculation");
  }
#endif // ASSERT

  if (!thread->can_call_java()) {
    // We do not care what kind of exception we get for a thread which
    // is compiling.  We just install a dummy exception object
    thread->set_pending_exception(Universe::vm_exception(), file, line);
    return true;
  }

  return false;
}

bool Exceptions::special_exception(JavaThread* thread, const char* file, int line, Symbol* h_name, const char* message) {
  // bootstrapping check
  if (!Universe::is_fully_initialized()) {
    if (h_name == NULL) {
      // atleast an informative message.
      vm_exit_during_initialization("Exception", message);
    } else {
      vm_exit_during_initialization(h_name, message);
    }
    ShouldNotReachHere();
  }

  if (!thread->can_call_java()) {
    // We do not care what kind of exception we get for a thread which
    // is compiling.  We just install a dummy exception object
    thread->set_pending_exception(Universe::vm_exception(), file, line);
    return true;
  }
  return false;
}

// This method should only be called from generated code,
// therefore the exception oop should be in the oopmap.
void Exceptions::_throw_oop(JavaThread* thread, const char* file, int line, oop exception) {
  assert(exception != NULL, "exception should not be NULL");
  Handle h_exception(thread, exception);
  _throw(thread, file, line, h_exception);
}

void Exceptions::_throw(JavaThread* thread, const char* file, int line, Handle h_exception, const char* message) {
  ResourceMark rm(thread);
  assert(h_exception() != NULL, "exception should not be NULL");

  // tracing (do this up front - so it works during boot strapping)
  // Note, the print_value_string() argument is not called unless logging is enabled!
  log_info(exceptions)("Exception <%s%s%s> (" INTPTR_FORMAT ") \n"
                       "thrown [%s, line %d]\nfor thread " INTPTR_FORMAT,
                       h_exception->print_value_string(),
                       message ? ": " : "", message ? message : "",
                       p2i(h_exception()), file, line, p2i(thread));

  // for AbortVMOnException flag
  Exceptions::debug_check_abort(h_exception, message);

  // Check for special boot-strapping/compiler-thread handling
  if (special_exception(thread, file, line, h_exception)) {
    return;
  }

  if (h_exception->is_a(vmClasses::OutOfMemoryError_klass())) {
    count_out_of_memory_exceptions(h_exception);
  }

  if (h_exception->is_a(vmClasses::LinkageError_klass())) {
    Atomic::inc(&_linkage_errors);
  }

  assert(h_exception->is_a(vmClasses::Throwable_klass()), "exception is not a subclass of java/lang/Throwable");

  // set the pending exception
  thread->set_pending_exception(h_exception(), file, line);

  // vm log
  Events::log_exception(thread, h_exception, message, file, line);
}


void Exceptions::_throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message,
                            Handle h_loader, Handle h_protection_domain) {
  // Check for special boot-strapping/compiler-thread handling
  if (special_exception(thread, file, line, name, message)) return;
  // Create and throw exception
  Handle h_cause(thread, NULL);
  Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);
  _throw(thread, file, line, h_exception, message);
}

void Exceptions::_throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause,
                                  Handle h_loader, Handle h_protection_domain) {
  // Check for special boot-strapping/compiler-thread handling
  if (special_exception(thread, file, line, name, message)) return;
  // Create and throw exception and init cause
  Handle h_exception = new_exception(thread, name, message, h_cause, h_loader, h_protection_domain);
  _throw(thread, file, line, h_exception, message);
}

void Exceptions::_throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause,
                              Handle h_loader, Handle h_protection_domain) {
  // Check for special boot-strapping/compiler-thread handling
  if (special_exception(thread, file, line, h_cause)) return;
  // Create and throw exception
  Handle h_exception = new_exception(thread, name, h_cause, h_loader, h_protection_domain);
  _throw(thread, file, line, h_exception, NULL);
}

void Exceptions::_throw_args(JavaThread* thread, const char* file, int line, Symbol* name, Symbol* signature, JavaCallArguments *args) {
  // Check for special boot-strapping/compiler-thread handling
  if (special_exception(thread, file, line, name, NULL)) return;
  // Create and throw exception
  Handle h_loader(thread, NULL);
  Handle h_prot(thread, NULL);
  Handle exception = new_exception(thread, name, signature, args, h_loader, h_prot);
  _throw(thread, file, line, exception);
}


// Methods for default parameters.
// NOTE: These must be here (and not in the header file) because of include circularities.
void Exceptions::_throw_msg_cause(JavaThread* thread, const char* file, int line, Symbol* name, const char* message, Handle h_cause) {
  _throw_msg_cause(thread, file, line, name, message, h_cause, Handle(thread, NULL), Handle(thread, NULL));
}
void Exceptions::_throw_msg(JavaThread* thread, const char* file, int line, Symbol* name, const char* message) {
  _throw_msg(thread, file, line, name, message, Handle(thread, NULL), Handle(thread, NULL));
}
void Exceptions::_throw_cause(JavaThread* thread, const char* file, int line, Symbol* name, Handle h_cause) {
  _throw_cause(thread, file, line, name, h_cause, Handle(thread, NULL), Handle(thread, NULL));
}


void Exceptions::throw_stack_overflow_exception(JavaThread* THREAD, const char* file, int line, const methodHandle& method) {
  Handle exception;
  if (!THREAD->has_pending_exception()) {
    InstanceKlass* k = vmClasses::StackOverflowError_klass();
    oop e = k->allocate_instance(CHECK);
    exception = Handle(THREAD, e);  // fill_in_stack trace does gc
    assert(k->is_initialized(), "need to increase java_thread_min_stack_allowed calculation");
    if (StackTraceInThrowable) {
      java_lang_Throwable::fill_in_stack_trace(exception, method);
    }
    // Increment counter for hs_err file reporting
    Atomic::inc(&Exceptions::_stack_overflow_errors);
  } else {
    // if prior exception, throw that one instead
    exception = Handle(THREAD, THREAD->pending_exception());
  }
  _throw(THREAD, file, line, exception);
}

void Exceptions::throw_unsafe_access_internal_error(JavaThread* thread, const char* file, int line, const char* message) {
  Handle h_exception = new_exception(thread, vmSymbols::java_lang_InternalError(), message);
  java_lang_InternalError::set_during_unsafe_access(h_exception());
  _throw(thread, file, line, h_exception, message);
}

void Exceptions::fthrow(JavaThread* thread, const char* file, int line, Symbol* h_name, const char* format, ...) {
  const int max_msg_size = 1024;
  va_list ap;
  va_start(ap, format);
  char msg[max_msg_size];
  os::vsnprintf(msg, max_msg_size, format, ap);
  va_end(ap);
  _throw_msg(thread, file, line, h_name, msg);
}


// Creates an exception oop, calls the <init> method with the given signature.
// and returns a Handle
Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
                                 Symbol* signature, JavaCallArguments *args,
                                 Handle h_loader, Handle h_protection_domain) {
  assert(Universe::is_fully_initialized(),
    "cannot be called during initialization");
  assert(!thread->has_pending_exception(), "already has exception");

  Handle h_exception;

  // Resolve exception klass, and check for pending exception below.
  Klass* klass = SystemDictionary::resolve_or_fail(name, h_loader, h_protection_domain, true, thread);

  if (!thread->has_pending_exception()) {
    assert(klass != NULL, "klass must exist");
    h_exception = JavaCalls::construct_new_instance(InstanceKlass::cast(klass),
                                signature,
                                args,
                                thread);
  }

  // Check if another exception was thrown in the process, if so rethrow that one
  if (thread->has_pending_exception()) {
    h_exception = Handle(thread, thread->pending_exception());
    thread->clear_pending_exception();
  }
  return h_exception;
}

// Creates an exception oop, calls the <init> method with the given signature.
// and returns a Handle
// Initializes the cause if cause non-null
Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
                                 Symbol* signature, JavaCallArguments *args,
                                 Handle h_cause,
                                 Handle h_loader, Handle h_protection_domain) {
  Handle h_exception = new_exception(thread, name, signature, args, h_loader, h_protection_domain);

  // Future: object initializer should take a cause argument
  if (h_cause.not_null()) {
    assert(h_cause->is_a(vmClasses::Throwable_klass()),
        "exception cause is not a subclass of java/lang/Throwable");
    JavaValue result1(T_OBJECT);
    JavaCallArguments args1;
    args1.set_receiver(h_exception);
    args1.push_oop(h_cause);
    JavaCalls::call_virtual(&result1, h_exception->klass(),
                                      vmSymbols::initCause_name(),
                                      vmSymbols::throwable_throwable_signature(),
                                      &args1,
                                      thread);
  }

  // Check if another exception was thrown in the process, if so rethrow that one
  if (thread->has_pending_exception()) {
    h_exception = Handle(thread, thread->pending_exception());
    thread->clear_pending_exception();
  }
  return h_exception;
}

// Convenience method. Calls either the <init>() or <init>(Throwable) method when
// creating a new exception
Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
                                 Handle h_cause,
                                 Handle h_loader, Handle h_protection_domain,
                                 ExceptionMsgToUtf8Mode to_utf8_safe) {
  JavaCallArguments args;
  Symbol* signature = NULL;
  if (h_cause.is_null()) {
    signature = vmSymbols::void_method_signature();
  } else {
    signature = vmSymbols::throwable_void_signature();
    args.push_oop(h_cause);
  }
  return new_exception(thread, name, signature, &args, h_loader, h_protection_domain);
}

// Convenience method. Calls either the <init>() or <init>(String) method when
// creating a new exception
Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
                                 const char* message, Handle h_cause,
                                 Handle h_loader, Handle h_protection_domain,
                                 ExceptionMsgToUtf8Mode to_utf8_safe) {
  JavaCallArguments args;
  Symbol* signature = NULL;
  if (message == NULL) {
    signature = vmSymbols::void_method_signature();
  } else {
    // We want to allocate storage, but we can't do that if there's
    // a pending exception, so we preserve any pending exception
    // around the allocation.
    // If we get an exception from the allocation, prefer that to
    // the exception we are trying to build, or the pending exception.
    // This is sort of like what PreserveExceptionMark does, except
    // for the preferencing and the early returns.
    Handle incoming_exception(thread, NULL);
    if (thread->has_pending_exception()) {
      incoming_exception = Handle(thread, thread->pending_exception());
      thread->clear_pending_exception();
    }
    Handle msg;
    if (to_utf8_safe == safe_to_utf8) {
      // Make a java UTF8 string.
      msg = java_lang_String::create_from_str(message, thread);
    } else {
      // Make a java string keeping the encoding scheme of the original string.
      msg = java_lang_String::create_from_platform_dependent_str(message, thread);
    }
    if (thread->has_pending_exception()) {
      Handle exception(thread, thread->pending_exception());
      thread->clear_pending_exception();
      return exception;
    }
    if (incoming_exception.not_null()) {
      return incoming_exception;
    }
    args.push_oop(msg);
    signature = vmSymbols::string_void_signature();
  }
  return new_exception(thread, name, signature, &args, h_cause, h_loader, h_protection_domain);
}

// Another convenience method that creates handles for null class loaders and
// protection domains and null causes.
// If the last parameter 'to_utf8_mode' is safe_to_utf8,
// it means we can safely ignore the encoding scheme of the message string and
// convert it directly to a java UTF8 string. Otherwise, we need to take the
// encoding scheme of the string into account. One thing we should do at some
// point is to push this flag down to class java_lang_String since other
// classes may need similar functionalities.
Handle Exceptions::new_exception(JavaThread* thread, Symbol* name,
                                 const char* message,
                                 ExceptionMsgToUtf8Mode to_utf8_safe) {

  Handle       h_loader(thread, NULL);
  Handle       h_prot(thread, NULL);
  Handle       h_cause(thread, NULL);
  return Exceptions::new_exception(thread, name, message, h_cause, h_loader,
                                   h_prot, to_utf8_safe);
}

// invokedynamic uses wrap_dynamic_exception for:
//    - bootstrap method resolution
//    - post call to MethodHandleNatives::linkCallSite
// dynamically computed constant uses wrap_dynamic_exception for:
//    - bootstrap method resolution
//    - post call to MethodHandleNatives::linkDynamicConstant
void Exceptions::wrap_dynamic_exception(bool is_indy, JavaThread* THREAD) {
  if (THREAD->has_pending_exception()) {
    bool log_indy = log_is_enabled(Debug, methodhandles, indy) && is_indy;
    bool log_condy = log_is_enabled(Debug, methodhandles, condy) && !is_indy;
    LogStreamHandle(Debug, methodhandles, indy) lsh_indy;
    LogStreamHandle(Debug, methodhandles, condy) lsh_condy;
    LogStream* ls = NULL;
    if (log_indy) {
      ls = &lsh_indy;
    } else if (log_condy) {
      ls = &lsh_condy;
    }
    oop exception = THREAD->pending_exception();

    // See the "Linking Exceptions" section for the invokedynamic instruction
    // in JVMS 6.5.
    if (exception->is_a(vmClasses::Error_klass())) {
      // Pass through an Error, including BootstrapMethodError, any other form
      // of linkage error, or say ThreadDeath/OutOfMemoryError
      if (ls != NULL) {
        ls->print_cr("bootstrap method invocation wraps BSME around " INTPTR_FORMAT, p2i((void *)exception));
        exception->print_on(ls);
      }
      return;
    }

    // Otherwise wrap the exception in a BootstrapMethodError
    if (ls != NULL) {
      ls->print_cr("%s throws BSME for " INTPTR_FORMAT, is_indy ? "invokedynamic" : "dynamic constant", p2i((void *)exception));
      exception->print_on(ls);
    }
    Handle nested_exception(THREAD, exception);
    THREAD->clear_pending_exception();
    THROW_CAUSE(vmSymbols::java_lang_BootstrapMethodError(), nested_exception)
  }
}

// Exception counting for hs_err file
volatile int Exceptions::_stack_overflow_errors = 0;
volatile int Exceptions::_linkage_errors = 0;
volatile int Exceptions::_out_of_memory_error_java_heap_errors = 0;
volatile int Exceptions::_out_of_memory_error_metaspace_errors = 0;
volatile int Exceptions::_out_of_memory_error_class_metaspace_errors = 0;

void Exceptions::count_out_of_memory_exceptions(Handle exception) {
  if (exception() == Universe::out_of_memory_error_metaspace()) {
     Atomic::inc(&_out_of_memory_error_metaspace_errors);
  } else if (exception() == Universe::out_of_memory_error_class_metaspace()) {
     Atomic::inc(&_out_of_memory_error_class_metaspace_errors);
  } else {
     // everything else reported as java heap OOM
     Atomic::inc(&_out_of_memory_error_java_heap_errors);
  }
}

void print_oom_count(outputStream* st, const char *err, int count) {
  if (count > 0) {
    st->print_cr("OutOfMemoryError %s=%d", err, count);
  }
}

bool Exceptions::has_exception_counts() {
  return (_stack_overflow_errors + _out_of_memory_error_java_heap_errors +
         _out_of_memory_error_metaspace_errors + _out_of_memory_error_class_metaspace_errors) > 0;
}

void Exceptions::print_exception_counts_on_error(outputStream* st) {
  print_oom_count(st, "java_heap_errors", _out_of_memory_error_java_heap_errors);
  print_oom_count(st, "metaspace_errors", _out_of_memory_error_metaspace_errors);
  print_oom_count(st, "class_metaspace_errors", _out_of_memory_error_class_metaspace_errors);
  if (_stack_overflow_errors > 0) {
    st->print_cr("StackOverflowErrors=%d", _stack_overflow_errors);
  }
  if (_linkage_errors > 0) {
    st->print_cr("LinkageErrors=%d", _linkage_errors);
  }
}

// Implementation of ExceptionMark

ExceptionMark::ExceptionMark(JavaThread* thread) {
  assert(thread == JavaThread::current(), "must be");
  _thread  = thread;
  check_no_pending_exception();
}

ExceptionMark::ExceptionMark() {
  _thread = JavaThread::current();
  check_no_pending_exception();
}

inline void ExceptionMark::check_no_pending_exception() {
  if (_thread->has_pending_exception()) {
    oop exception = _thread->pending_exception();
    _thread->clear_pending_exception(); // Needed to avoid infinite recursion
    exception->print();
    fatal("ExceptionMark constructor expects no pending exceptions");
  }
}


ExceptionMark::~ExceptionMark() {
  if (_thread->has_pending_exception()) {
    Handle exception(_thread, _thread->pending_exception());
    _thread->clear_pending_exception(); // Needed to avoid infinite recursion
    if (is_init_completed()) {
      exception->print();
      fatal("ExceptionMark destructor expects no pending exceptions");
    } else {
      vm_exit_during_initialization(exception);
    }
  }
}

// ----------------------------------------------------------------------------------------

// caller frees value_string if necessary
void Exceptions::debug_check_abort(const char *value_string, const char* message) {
  if (AbortVMOnException != NULL && value_string != NULL &&
      strstr(value_string, AbortVMOnException)) {
    if (AbortVMOnExceptionMessage == NULL || (message != NULL &&
        strstr(message, AbortVMOnExceptionMessage))) {
      fatal("Saw %s, aborting", value_string);
    }
  }
}

void Exceptions::debug_check_abort(Handle exception, const char* message) {
  if (AbortVMOnException != NULL) {
    debug_check_abort_helper(exception, message);
  }
}

void Exceptions::debug_check_abort_helper(Handle exception, const char* message) {
  ResourceMark rm;
  if (message == NULL && exception->is_a(vmClasses::Throwable_klass())) {
    oop msg = java_lang_Throwable::message(exception());
    if (msg != NULL) {
      message = java_lang_String::as_utf8_string(msg);
    }
  }
  debug_check_abort(exception()->klass()->external_name(), message);
}

// for logging exceptions
void Exceptions::log_exception(Handle exception, const char* message) {
  ResourceMark rm;
  Symbol* detail_message = java_lang_Throwable::detail_message(exception());
  if (detail_message != NULL) {
    log_info(exceptions)("Exception <%s: %s>\n thrown in %s",
                         exception->print_value_string(),
                         detail_message->as_C_string(),
                         message);
  } else {
    log_info(exceptions)("Exception <%s>\n thrown in %s",
                         exception->print_value_string(),
                         message);
  }
}