/*
* Copyright (c) 2015, 2018, 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/javaClasses.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "classfile/vmSymbols.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/oopFactory.hpp"
#include "oops/oop.inline.hpp"
#include "oops/objArrayOop.inline.hpp"
#include "prims/stackwalk.hpp"
#include "runtime/globals.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/vframe.inline.hpp"
#include "utilities/globalDefinitions.hpp"
// setup and cleanup actions
void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
frames_array->obj_at_put(magic_pos, _thread->threadObj());
_anchor = address_value();
assert(check_magic(frames_array), "invalid magic");
}
bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
oop m1 = frames_array->obj_at(magic_pos);
jlong m2 = _anchor;
if (oopDesc::equals(m1, _thread->threadObj()) && m2 == address_value()) return true;
return false;
}
bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
bool ok = check_magic(frames_array);
frames_array->obj_at_put(magic_pos, NULL);
_anchor = 0L;
return ok;
}
JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
: BaseFrameStream(thread), _vfst(thread) {
_need_method_info = StackWalk::need_method_info(mode);
}
void JavaFrameStream::next() { _vfst.next();}
// Returns the BaseFrameStream for the current stack being traversed.
//
// Parameters:
// thread Current Java thread.
// magic Magic value used for each stack walking
// frames_array User-supplied buffers. The 0th element is reserved
// for this BaseFrameStream to use
//
BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
objArrayHandle frames_array)
{
assert(thread != NULL && thread->is_Java_thread(), "");
oop m1 = frames_array->obj_at(magic_pos);
if (!oopDesc::equals(m1, thread->threadObj())) return NULL;
if (magic == 0L) return NULL;
BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
if (!stream->is_valid_in(thread, frames_array)) return NULL;
return stream;
}
// Unpacks one or more frames into user-supplied buffers.
// Updates the end index, and returns the number of unpacked frames.
// Always start with the existing vfst.method and bci.
// Do not call vfst.next to advance over the last returned value.
// In other words, do not leave any stale data in the vfst.
//
// Parameters:
// mode Restrict which frames to be decoded.
// BaseFrameStream stream of frames
// max_nframes Maximum number of frames to be filled.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store Class or StackFrame in, starting at start_index.
// frames array is a Class<?>[] array when only getting caller
// reference, and a StackFrameInfo[] array (or derivative)
// otherwise. It should never be null.
// end_index End index to the user-supplied buffers with unpacked frames.
//
// Returns the number of frames whose information was transferred into the buffers.
//
int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
int max_nframes, int start_index,
objArrayHandle frames_array,
int& end_index, TRAPS) {
log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
max_nframes, start_index, frames_array->length());
assert(max_nframes > 0, "invalid max_nframes");
assert(start_index + max_nframes <= frames_array->length(), "oob");
int frames_decoded = 0;
for (; !stream.at_end(); stream.next()) {
Method* method = stream.method();
if (method == NULL) continue;
// skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
// not set) and when StackWalker::getCallerClass is called
if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
if (method->is_hidden()) {
LogTarget(Debug, stackwalk) lt;
if (lt.is_enabled()) {
ResourceMark rm(THREAD);
LogStream ls(lt);
ls.print(" hidden method: ");
method->print_short_name(&ls);
ls.cr();
}
continue;
}
}
int index = end_index++;
LogTarget(Debug, stackwalk) lt;
if (lt.is_enabled()) {
ResourceMark rm(THREAD);
LogStream ls(lt);
ls.print(" %d: frame method: ", index);
method->print_short_name(&ls);
ls.print_cr(" bci=%d", stream.bci());
}
if (!need_method_info(mode) && get_caller_class(mode) &&
index == start_index && method->caller_sensitive()) {
ResourceMark rm(THREAD);
THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
err_msg("StackWalker::getCallerClass called from @CallerSensitive %s method",
method->name_and_sig_as_C_string()));
}
// fill in StackFrameInfo and initialize MemberName
stream.fill_frame(index, frames_array, method, CHECK_0);
if (++frames_decoded >= max_nframes) break;
}
return frames_decoded;
}
// Fill in the LiveStackFrameInfo at the given index in frames_array
void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array,
const methodHandle& method, TRAPS) {
Handle stackFrame(THREAD, frames_array->obj_at(index));
fill_live_stackframe(stackFrame, method, CHECK);
}
// Fill in the StackFrameInfo at the given index in frames_array
void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array,
const methodHandle& method, TRAPS) {
if (_need_method_info) {
Handle stackFrame(THREAD, frames_array->obj_at(index));
fill_stackframe(stackFrame, method, CHECK);
} else {
frames_array->obj_at_put(index, method->method_holder()->java_mirror());
}
}
// Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
// StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
// T_OBJECT, or T_CONFLICT.
oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
int i, BasicType type, TRAPS) {
Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
InstanceKlass* ik = InstanceKlass::cast(k);
JavaValue result(T_OBJECT);
JavaCallArguments args;
Symbol* signature = NULL;
// ## TODO: type is only available in LocalVariable table, if present.
// ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
switch (type) {
case T_INT:
args.push_int(values->int_at(i));
signature = vmSymbols::asPrimitive_int_signature();
break;
case T_LONG:
args.push_long(values->long_at(i));
signature = vmSymbols::asPrimitive_long_signature();
break;
case T_FLOAT:
case T_DOUBLE:
case T_BYTE:
case T_SHORT:
case T_CHAR:
case T_BOOLEAN:
THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL);
case T_OBJECT:
return values->obj_at(i)();
case T_CONFLICT:
// put a non-null slot
#ifdef _LP64
args.push_long(0);
signature = vmSymbols::asPrimitive_long_signature();
#else
args.push_int(0);
signature = vmSymbols::asPrimitive_int_signature();
#endif
break;
default: ShouldNotReachHere();
}
JavaCalls::call_static(&result,
ik,
vmSymbols::asPrimitive_name(),
signature,
&args,
CHECK_NULL);
return (instanceOop) result.get_jobject();
}
objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
objArrayHandle empty;
int length = values->size();
objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
length, CHECK_(empty));
objArrayHandle array_h(THREAD, array_oop);
for (int i = 0; i < values->size(); i++) {
StackValue* st = values->at(i);
BasicType type = st->type();
int index = i;
#ifdef _LP64
if (type != T_OBJECT && type != T_CONFLICT) {
intptr_t ret = st->get_int(); // read full 64-bit slot
type = T_LONG; // treat as long
index--; // undo +1 in StackValueCollection::long_at
}
#endif
oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty));
if (obj != NULL) {
array_h->obj_at_put(i, obj);
}
}
return array_h;
}
objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
int length = monitors->length();
objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
length, CHECK_(objArrayHandle()));
objArrayHandle array_h(THREAD, array_oop);
for (int i = 0; i < length; i++) {
MonitorInfo* monitor = monitors->at(i);
array_h->obj_at_put(i, monitor->owner());
}
return array_h;
}
// Fill StackFrameInfo with bci and initialize memberName
void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS) {
java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD);
}
// Fill LiveStackFrameInfo with locals, monitors, and expressions
void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
const methodHandle& method, TRAPS) {
fill_stackframe(stackFrame, method, CHECK);
if (_jvf != NULL) {
StackValueCollection* locals = _jvf->locals();
StackValueCollection* expressions = _jvf->expressions();
GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
int mode = 0;
if (_jvf->is_interpreted_frame()) {
mode = MODE_INTERPRETED;
} else if (_jvf->is_compiled_frame()) {
mode = MODE_COMPILED;
}
if (!locals->is_empty()) {
objArrayHandle locals_h = values_to_object_array(locals, CHECK);
java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
}
if (!expressions->is_empty()) {
objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
}
if (monitors->length() > 0) {
objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
}
java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
}
}
// Begins stack walking.
//
// Parameters:
// stackStream StackStream object
// mode Stack walking mode.
// skip_frames Number of frames to be skipped.
// frame_count Number of frames to be traversed.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store StackFrame in, starting at start_index.
// frames array is a Class<?>[] array when only getting caller
// reference, and a StackFrameInfo[] array (or derivative)
// otherwise. It should never be null.
//
// Returns Object returned from AbstractStackWalker::doStackWalk call.
//
oop StackWalk::walk(Handle stackStream, jlong mode,
int skip_frames, int frame_count, int start_index,
objArrayHandle frames_array,
TRAPS) {
ResourceMark rm(THREAD);
JavaThread* jt = (JavaThread*)THREAD;
log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
mode, skip_frames, frame_count);
if (frames_array.is_null()) {
THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
}
// Setup traversal onto my stack.
if (live_frame_info(mode)) {
assert (use_frames_array(mode), "Bad mode for get live frame");
RegisterMap regMap(jt, true);
LiveFrameStream stream(jt, ®Map);
return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
start_index, frames_array, THREAD);
} else {
JavaFrameStream stream(jt, mode);
return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
start_index, frames_array, THREAD);
}
}
oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
jlong mode, int skip_frames, int frame_count,
int start_index, objArrayHandle frames_array, TRAPS) {
methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
{
Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
while (!stream.at_end()) {
InstanceKlass* ik = stream.method()->method_holder();
if (ik != stackWalker_klass &&
ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
break;
}
LogTarget(Debug, stackwalk) lt;
if (lt.is_enabled()) {
ResourceMark rm(THREAD);
LogStream ls(lt);
ls.print(" skip ");
stream.method()->print_short_name(&ls);
ls.cr();
}
stream.next();
}
// stack frame has been traversed individually and resume stack walk
// from the stack frame at depth == skip_frames.
for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
LogTarget(Debug, stackwalk) lt;
if (lt.is_enabled()) {
ResourceMark rm(THREAD);
LogStream ls(lt);
ls.print(" skip ");
stream.method()->print_short_name(&ls);
ls.cr();
}
}
}
int end_index = start_index;
int numFrames = 0;
if (!stream.at_end()) {
numFrames = fill_in_frames(mode, stream, frame_count, start_index,
frames_array, end_index, CHECK_NULL);
if (numFrames < 1) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
}
}
// JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
// Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
// which calls the implementation to consume the stack frames.
// When JVM_CallStackWalk returns, it invalidates the stack stream.
JavaValue result(T_OBJECT);
JavaCallArguments args(stackStream);
args.push_long(stream.address_value());
args.push_int(skip_frames);
args.push_int(frame_count);
args.push_int(start_index);
args.push_int(end_index);
// Link the thread and vframe stream into the callee-visible object
stream.setup_magic_on_entry(frames_array);
JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
// Do this before anything else happens, to disable any lingering stream objects
bool ok = stream.cleanup_magic_on_exit(frames_array);
// Throw pending exception if we must
(void) (CHECK_NULL);
if (!ok) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
}
// Return normally
return (oop)result.get_jobject();
}
// Walk the next batch of stack frames
//
// Parameters:
// stackStream StackStream object
// mode Stack walking mode.
// magic Must be valid value to continue the stack walk
// frame_count Number of frames to be decoded.
// start_index Start index to the user-supplied buffers.
// frames_array Buffer to store StackFrame in, starting at start_index.
//
// Returns the end index of frame filled in the buffer.
//
jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
int frame_count, int start_index,
objArrayHandle frames_array,
TRAPS)
{
JavaThread* jt = (JavaThread*)THREAD;
BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
if (existing_stream == NULL) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
}
if (frames_array.is_null()) {
THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
}
log_debug(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
PTR_FORMAT " start %d frames %d",
frame_count, p2i(existing_stream), start_index, frames_array->length());
int end_index = start_index;
if (frame_count <= 0) {
return end_index; // No operation.
}
int count = frame_count + start_index;
assert (frames_array->length() >= count, "not enough space in buffers");
BaseFrameStream& stream = (*existing_stream);
if (!stream.at_end()) {
stream.next(); // advance past the last frame decoded in previous batch
if (!stream.at_end()) {
int n = fill_in_frames(mode, stream, frame_count, start_index,
frames_array, end_index, CHECK_0);
if (n < 1) {
THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
}
return end_index;
}
}
return end_index;
}