/*
* Copyright (c) 2015, 2017, 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/classFileParser.hpp"
#include "classfile/classFileStream.hpp"
#include "classfile/classLoader.hpp"
#include "classfile/classLoaderData.hpp"
#include "classfile/classLoaderData.inline.hpp"
#include "classfile/klassFactory.hpp"
#include "classfile/sharedClassUtil.hpp"
#include "memory/metaspaceShared.hpp"
#include "memory/resourceArea.hpp"
#include "prims/jvmtiEnvBase.hpp"
#include "prims/jvmtiRedefineClasses.hpp"
#include "trace/traceMacros.hpp"
// called during initial loading of a shared class
InstanceKlass* KlassFactory::check_shared_class_file_load_hook(
InstanceKlass* ik,
Symbol* class_name,
Handle class_loader,
Handle protection_domain, TRAPS) {
#if INCLUDE_CDS && INCLUDE_JVMTI
assert(ik != NULL, "sanity");
assert(ik->is_shared(), "expecting a shared class");
if (JvmtiExport::should_post_class_file_load_hook()) {
assert(THREAD->is_Java_thread(), "must be JavaThread");
// Post the CFLH
JvmtiCachedClassFileData* cached_class_file = NULL;
JvmtiCachedClassFileData* archived_class_data = ik->get_archived_class_data();
assert(archived_class_data != NULL, "shared class has no archived class data");
unsigned char* ptr =
VM_RedefineClasses::get_cached_class_file_bytes(archived_class_data);
unsigned char* end_ptr =
ptr + VM_RedefineClasses::get_cached_class_file_len(archived_class_data);
unsigned char* old_ptr = ptr;
JvmtiExport::post_class_file_load_hook(class_name,
class_loader,
protection_domain,
&ptr,
&end_ptr,
&cached_class_file);
if (old_ptr != ptr) {
// JVMTI agent has modified class file data.
// Set new class file stream using JVMTI agent modified class file data.
ClassLoaderData* loader_data =
ClassLoaderData::class_loader_data(class_loader());
int path_index = ik->shared_classpath_index();
const char* pathname;
if (path_index < 0) {
// shared classes loaded by user defined class loader
// do not have shared_classpath_index
ModuleEntry* mod_entry = ik->module();
if (mod_entry != NULL && (mod_entry->location() != NULL)) {
ResourceMark rm;
pathname = (const char*)(mod_entry->location()->as_C_string());
} else {
pathname = "";
}
} else {
SharedClassPathEntry* ent =
(SharedClassPathEntry*)FileMapInfo::shared_classpath(path_index);
pathname = ent == NULL ? NULL : ent->name();
}
ClassFileStream* stream = new ClassFileStream(ptr,
end_ptr - ptr,
pathname,
ClassFileStream::verify);
ClassFileParser parser(stream,
class_name,
loader_data,
protection_domain,
NULL,
NULL,
ClassFileParser::BROADCAST, // publicity level
CHECK_NULL);
InstanceKlass* new_ik = parser.create_instance_klass(true /* changed_by_loadhook */,
CHECK_NULL);
if (cached_class_file != NULL) {
new_ik->set_cached_class_file(cached_class_file);
}
if (class_loader.is_null()) {
ResourceMark rm;
ClassLoader::add_package(class_name->as_C_string(), path_index, THREAD);
}
return new_ik;
}
}
#endif
return NULL;
}
static ClassFileStream* check_class_file_load_hook(ClassFileStream* stream,
Symbol* name,
ClassLoaderData* loader_data,
Handle protection_domain,
JvmtiCachedClassFileData** cached_class_file,
TRAPS) {
assert(stream != NULL, "invariant");
if (JvmtiExport::should_post_class_file_load_hook()) {
assert(THREAD->is_Java_thread(), "must be a JavaThread");
const JavaThread* jt = (JavaThread*)THREAD;
Handle class_loader(THREAD, loader_data->class_loader());
// Get the cached class file bytes (if any) from the class that
// is being redefined or retransformed. We use jvmti_thread_state()
// instead of JvmtiThreadState::state_for(jt) so we don't allocate
// a JvmtiThreadState any earlier than necessary. This will help
// avoid the bug described by 7126851.
JvmtiThreadState* state = jt->jvmti_thread_state();
if (state != NULL) {
Klass* k = state->get_class_being_redefined();
if (k != NULL) {
InstanceKlass* class_being_redefined = InstanceKlass::cast(k);
*cached_class_file = class_being_redefined->get_cached_class_file();
}
}
unsigned char* ptr = const_cast<unsigned char*>(stream->buffer());
unsigned char* end_ptr = ptr + stream->length();
JvmtiExport::post_class_file_load_hook(name,
class_loader,
protection_domain,
&ptr,
&end_ptr,
cached_class_file);
if (ptr != stream->buffer()) {
// JVMTI agent has modified class file data.
// Set new class file stream using JVMTI agent modified class file data.
stream = new ClassFileStream(ptr,
end_ptr - ptr,
stream->source(),
stream->need_verify());
}
}
return stream;
}
InstanceKlass* KlassFactory::create_from_stream(ClassFileStream* stream,
Symbol* name,
ClassLoaderData* loader_data,
Handle protection_domain,
const InstanceKlass* host_klass,
GrowableArray<Handle>* cp_patches,
TRAPS) {
assert(stream != NULL, "invariant");
assert(loader_data != NULL, "invariant");
assert(THREAD->is_Java_thread(), "must be a JavaThread");
ResourceMark rm;
HandleMark hm;
JvmtiCachedClassFileData* cached_class_file = NULL;
ClassFileStream* old_stream = stream;
// Skip this processing for VM anonymous classes
if (host_klass == NULL) {
stream = check_class_file_load_hook(stream,
name,
loader_data,
protection_domain,
&cached_class_file,
CHECK_NULL);
}
ClassFileParser parser(stream,
name,
loader_data,
protection_domain,
host_klass,
cp_patches,
ClassFileParser::BROADCAST, // publicity level
CHECK_NULL);
InstanceKlass* result = parser.create_instance_klass(old_stream != stream, CHECK_NULL);
assert(result == parser.create_instance_klass(old_stream != stream, THREAD), "invariant");
if (result == NULL) {
return NULL;
}
if (cached_class_file != NULL) {
// JVMTI: we have an InstanceKlass now, tell it about the cached bytes
result->set_cached_class_file(cached_class_file);
}
if (result->should_store_fingerprint()) {
result->store_fingerprint(stream->compute_fingerprint());
}
TRACE_KLASS_CREATION(result, parser, THREAD);
#if INCLUDE_CDS
if (DumpSharedSpaces) {
ClassLoader::record_shared_class_loader_type(result, stream);
#if INCLUDE_JVMTI
assert(cached_class_file == NULL, "Sanity");
// Archive the class stream data into the optional data section
JvmtiCachedClassFileData *p;
int len;
const unsigned char *bytes;
// event based tracing might set cached_class_file
if ((bytes = result->get_cached_class_file_bytes()) != NULL) {
len = result->get_cached_class_file_len();
} else {
len = stream->length();
bytes = stream->buffer();
}
p = (JvmtiCachedClassFileData*)os::malloc(offset_of(JvmtiCachedClassFileData, data) + len, mtInternal);
p->length = len;
memcpy(p->data, bytes, len);
result->set_archived_class_data(p);
#endif // INCLUDE_JVMTI
}
#endif // INCLUDE_CDS
return result;
}