/*

 * Copyright (c) 1998, 2012, 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.

 *

 */

#include "precompiled.hpp"

#include "classfile/classFileStream.hpp"

#include "classfile/javaClasses.hpp"

#include "classfile/stackMapTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/verifier.hpp"

#include "classfile/vmSymbols.hpp"

#include "interpreter/bytecodeStream.hpp"

#include "memory/oopFactory.hpp"

#include "memory/resourceArea.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/oop.inline.hpp"

#include "oops/typeArrayOop.hpp"

#include "prims/jvm.h"

#include "runtime/fieldDescriptor.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/interfaceSupport.hpp"

#include "runtime/javaCalls.hpp"

#include "runtime/orderAccess.hpp"

#include "runtime/os.hpp"

#ifdef TARGET_ARCH_x86

# include "bytes_x86.hpp"

#endif

#ifdef TARGET_ARCH_sparc

# include "bytes_sparc.hpp"

#endif

#ifdef TARGET_ARCH_zero

# include "bytes_zero.hpp"

#endif

#ifdef TARGET_ARCH_arm

# include "bytes_arm.hpp"

#endif

#ifdef TARGET_ARCH_ppc

# include "bytes_ppc.hpp"

#endif

#define NOFAILOVER_MAJOR_VERSION 51

// Access to external entry for VerifyClassCodes - old byte code verifier

extern "C" {

  typedef jboolean (*verify_byte_codes_fn_t)(JNIEnv *, jclass, char *, jint);

  typedef jboolean (*verify_byte_codes_fn_new_t)(JNIEnv *, jclass, char *, jint, jint);

}

static void* volatile _verify_byte_codes_fn = NULL;

static volatile jint _is_new_verify_byte_codes_fn = (jint) true;

static void* verify_byte_codes_fn() {

  if (_verify_byte_codes_fn == NULL) {

    void *lib_handle = os::native_java_library();

    void *func = os::dll_lookup(lib_handle, "VerifyClassCodesForMajorVersion");

    OrderAccess::release_store_ptr(&_verify_byte_codes_fn, func);

    if (func == NULL) {

      OrderAccess::release_store(&_is_new_verify_byte_codes_fn, false);

      func = os::dll_lookup(lib_handle, "VerifyClassCodes");

      OrderAccess::release_store_ptr(&_verify_byte_codes_fn, func);

    }

  }

  return (void*)_verify_byte_codes_fn;

}

// Methods in Verifier

bool Verifier::should_verify_for(oop class_loader, bool should_verify_class) {

  return (class_loader == NULL || !should_verify_class) ?

    BytecodeVerificationLocal : BytecodeVerificationRemote;

}

bool Verifier::relax_verify_for(oop loader) {

  bool trusted = java_lang_ClassLoader::is_trusted_loader(loader);

  bool need_verify =

    // verifyAll

    (BytecodeVerificationLocal && BytecodeVerificationRemote) ||

    // verifyRemote

    (!BytecodeVerificationLocal && BytecodeVerificationRemote && !trusted);

  return !need_verify;

}

bool Verifier::verify(instanceKlassHandle klass, Verifier::Mode mode, bool should_verify_class, TRAPS) {

  HandleMark hm;

  ResourceMark rm(THREAD);

  Symbol* exception_name = NULL;

  const size_t message_buffer_len = klass->name()->utf8_length() + 1024;

  char* message_buffer = NEW_RESOURCE_ARRAY(char, message_buffer_len);

  const char* klassName = klass->external_name();

  // If the class should be verified, first see if we can use the split

  // verifier.  If not, or if verification fails and FailOverToOldVerifier

  // is set, then call the inference verifier.

  if (is_eligible_for_verification(klass, should_verify_class)) {

    if (TraceClassInitialization) {

      tty->print_cr("Start class verification for: %s", klassName);

    }

    if (UseSplitVerifier &&

        klass->major_version() >= STACKMAP_ATTRIBUTE_MAJOR_VERSION) {

          (exception_name == vmSymbols::java_lang_VerifyError() ||

           exception_name == vmSymbols::java_lang_ClassFormatError())) {

          tty->print_cr(

            "Fail over class verification to old verifier for: %s", klassName);

        }

        exception_name = inference_verify(

          klass, message_buffer, message_buffer_len, THREAD);

      }

    } else {

      exception_name = inference_verify(

          klass, message_buffer, message_buffer_len, THREAD);

    }

      if (HAS_PENDING_EXCEPTION) {

        tty->print("Verification for %s has", klassName);

        tty->print_cr(" exception pending %s ",

          instanceKlass::cast(PENDING_EXCEPTION->klass())->external_name());

      } else if (exception_name != NULL) {

        tty->print_cr("Verification for %s failed", klassName);

      }

      tty->print_cr("End class verification for: %s", klassName);

    }

  }

  if (HAS_PENDING_EXCEPTION) {

    return false; // use the existing exception

  } else if (exception_name == NULL) {

    return true; // verifcation succeeded

  } else { // VerifyError or ClassFormatError to be created and thrown

    ResourceMark rm(THREAD);

    instanceKlassHandle kls =

      SystemDictionary::resolve_or_fail(exception_name, true, CHECK_false);

    while (!kls.is_null()) {

      if (kls == klass) {

        // If the class being verified is the exception we're creating

        // or one of it's superclasses, we're in trouble and are going

        // to infinitely recurse when we try to initialize the exception.

        // So bail out here by throwing the preallocated VM error.

        THROW_OOP_(Universe::virtual_machine_error_instance(), false);

      }

      kls = kls->super();

    }

    message_buffer[message_buffer_len - 1] = '\0'; // just to be sure

  }

}

bool Verifier::is_eligible_for_verification(instanceKlassHandle klass, bool should_verify_class) {

  Symbol* name = klass->name();

  klassOop refl_magic_klass = SystemDictionary::reflect_MagicAccessorImpl_klass();

  return (should_verify_for(klass->class_loader(), should_verify_class) &&

    // return if the class is a bootstrapping class

    // or defineClass specified not to verify by default (flags override passed arg)

    // We need to skip the following four for bootstraping

    name != vmSymbols::java_lang_Object() &&

    name != vmSymbols::java_lang_Class() &&

    name != vmSymbols::java_lang_String() &&

    name != vmSymbols::java_lang_Throwable() &&

    // Can not verify the bytecodes for shared classes because they have

    // already been rewritten to contain constant pool cache indices,

    // which the verifier can't understand.

    // Shared classes shouldn't have stackmaps either.

    !klass()->is_shared() &&

    // As of the fix for 4486457 we disable verification for all of the

    // dynamically-generated bytecodes associated with the 1.4

    // reflection implementation, not just those associated with

    // sun/reflect/SerializationConstructorAccessor.

    // NOTE: this is called too early in the bootstrapping process to be

    // guarded by Universe::is_gte_jdk14x_version()/UseNewReflection.

    (refl_magic_klass == NULL ||

     !klass->is_subtype_of(refl_magic_klass) ||

     VerifyReflectionBytecodes)

  );

}

Symbol* Verifier::inference_verify(

    instanceKlassHandle klass, char* message, size_t message_len, TRAPS) {

  JavaThread* thread = (JavaThread*)THREAD;

  JNIEnv *env = thread->jni_environment();

  void* verify_func = verify_byte_codes_fn();

  if (verify_func == NULL) {

    jio_snprintf(message, message_len, "Could not link verifier");

    return vmSymbols::java_lang_VerifyError();

  }

  ResourceMark rm(THREAD);

    tty->print_cr("Verifying class %s with old format", klass->external_name());

  }

  jclass cls = (jclass) JNIHandles::make_local(env, klass->java_mirror());

  jint result;

  {

    HandleMark hm(thread);

    ThreadToNativeFromVM ttn(thread);

    // ThreadToNativeFromVM takes care of changing thread_state, so safepoint

    // code knows that we have left the VM

    if (_is_new_verify_byte_codes_fn) {

      verify_byte_codes_fn_new_t func =

        CAST_TO_FN_PTR(verify_byte_codes_fn_new_t, verify_func);

      result = (*func)(env, cls, message, (int)message_len,

          klass->major_version());

    } else {

      verify_byte_codes_fn_t func =

        CAST_TO_FN_PTR(verify_byte_codes_fn_t, verify_func);

      result = (*func)(env, cls, message, (int)message_len);

    }

  }

  JNIHandles::destroy_local(cls);

  // These numbers are chosen so that VerifyClassCodes interface doesn't need

  // to be changed (still return jboolean (unsigned char)), and result is

  // 1 when verification is passed.

  if (result == 0) {

    return vmSymbols::java_lang_VerifyError();

  } else if (result == 1) {

    return NULL; // verified.

  } else if (result == 2) {

    THROW_MSG_(vmSymbols::java_lang_OutOfMemoryError(), message, NULL);

  } else if (result == 3) {

    return vmSymbols::java_lang_ClassFormatError();

  } else {

    ShouldNotReachHere();

    return NULL;

  }

}