--- /dev/null 2018-02-03 04:43:52.625000053 -0500 +++ new/src/hotspot/share/runtime/vframe.inline.hpp 2018-03-20 18:41:16.101345828 -0400 @@ -0,0 +1,224 @@ +/* + * Copyright (c) 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. + * + */ + +#ifndef SHARE_VM_RUNTIME_VFRAME_INLINE_HPP +#define SHARE_VM_RUNTIME_VFRAME_INLINE_HPP + +#include "runtime/frame.inline.hpp" +#include "runtime/vframe.hpp" + +inline vframeStreamCommon::vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) { + _thread = thread; +} + +inline intptr_t* vframeStreamCommon::frame_id() const { return _frame.id(); } + +inline bool vframeStreamCommon::is_interpreted_frame() const { return _frame.is_interpreted_frame(); } + +inline bool vframeStreamCommon::is_entry_frame() const { return _frame.is_entry_frame(); } + +inline void vframeStreamCommon::next() { + // handle frames with inlining + if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) return; + + // handle general case + do { + _frame = _frame.sender(&_reg_map); + } while (!fill_from_frame()); +} + +inline vframeStream::vframeStream(JavaThread* thread, bool stop_at_java_call_stub) + : vframeStreamCommon(thread) { + _stop_at_java_call_stub = stop_at_java_call_stub; + + if (!thread->has_last_Java_frame()) { + _mode = at_end_mode; + return; + } + + _frame = _thread->last_frame(); + while (!fill_from_frame()) { + _frame = _frame.sender(&_reg_map); + } +} + +inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() { + if (_sender_decode_offset == DebugInformationRecorder::serialized_null) { + return false; + } + fill_from_compiled_frame(_sender_decode_offset); + return true; +} + + +inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) { + _mode = compiled_mode; + + // Range check to detect ridiculous offsets. + if (decode_offset == DebugInformationRecorder::serialized_null || + decode_offset < 0 || + decode_offset >= nm()->scopes_data_size()) { + // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. + // If we read nmethod::scopes_data at serialized_null (== 0) + // or if read some at other invalid offset, invalid values will be decoded. + // Based on these values, invalid heap locations could be referenced + // that could lead to crashes in product mode. + // Therefore, do not use the decode offset if invalid, but fill the frame + // as it were a native compiled frame (no Java-level assumptions). +#ifdef ASSERT + if (WizardMode) { + ttyLocker ttyl; + tty->print_cr("Error in fill_from_frame: pc_desc for " + INTPTR_FORMAT " not found or invalid at %d", + p2i(_frame.pc()), decode_offset); + nm()->print(); + nm()->method()->print_codes(); + nm()->print_code(); + nm()->print_pcs(); + } + found_bad_method_frame(); +#endif + // Provide a cheap fallback in product mode. (See comment above.) + fill_from_compiled_native_frame(); + return; + } + + // Decode first part of scopeDesc + DebugInfoReadStream buffer(nm(), decode_offset); + _sender_decode_offset = buffer.read_int(); + _method = buffer.read_method(); + _bci = buffer.read_bci(); + + assert(_method->is_method(), "checking type of decoded method"); +} + +// The native frames are handled specially. We do not rely on ScopeDesc info +// since the pc might not be exact due to the _last_native_pc trick. +inline void vframeStreamCommon::fill_from_compiled_native_frame() { + _mode = compiled_mode; + _sender_decode_offset = DebugInformationRecorder::serialized_null; + _method = nm()->method(); + _bci = 0; +} + +inline bool vframeStreamCommon::fill_from_frame() { + // Interpreted frame + if (_frame.is_interpreted_frame()) { + fill_from_interpreter_frame(); + return true; + } + + // Compiled frame + + if (cb() != NULL && cb()->is_compiled()) { + if (nm()->is_native_method()) { + // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick. + fill_from_compiled_native_frame(); + } else { + PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc()); + int decode_offset; + if (pc_desc == NULL) { + // Should not happen, but let fill_from_compiled_frame handle it. + + // If we are trying to walk the stack of a thread that is not + // at a safepoint (like AsyncGetCallTrace would do) then this is an + // acceptable result. [ This is assuming that safe_for_sender + // is so bullet proof that we can trust the frames it produced. ] + // + // So if we see that the thread is not safepoint safe + // then simply produce the method and a bci of zero + // and skip the possibility of decoding any inlining that + // may be present. That is far better than simply stopping (or + // asserting. If however the thread is safepoint safe this + // is the sign of a compiler bug and we'll let + // fill_from_compiled_frame handle it. + + + JavaThreadState state = _thread->thread_state(); + + // in_Java should be good enough to test safepoint safety + // if state were say in_Java_trans then we'd expect that + // the pc would have already been slightly adjusted to + // one that would produce a pcDesc since the trans state + // would be one that might in fact anticipate a safepoint + + if (state == _thread_in_Java ) { + // This will get a method a zero bci and no inlining. + // Might be nice to have a unique bci to signify this + // particular case but for now zero will do. + + fill_from_compiled_native_frame(); + + // There is something to be said for setting the mode to + // at_end_mode to prevent trying to walk further up the + // stack. There is evidence that if we walk any further + // that we could produce a bad stack chain. However until + // we see evidence that allowing this causes us to find + // frames bad enough to cause segv's or assertion failures + // we don't do it as while we may get a bad call chain the + // probability is much higher (several magnitudes) that we + // get good data. + + return true; + } + decode_offset = DebugInformationRecorder::serialized_null; + } else { + decode_offset = pc_desc->scope_decode_offset(); + } + fill_from_compiled_frame(decode_offset); + } + return true; + } + + // End of stack? + if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) { + _mode = at_end_mode; + return true; + } + + return false; +} + + +inline void vframeStreamCommon::fill_from_interpreter_frame() { + Method* method = _frame.interpreter_frame_method(); + address bcp = _frame.interpreter_frame_bcp(); + int bci = method->validate_bci_from_bcp(bcp); + // 6379830 AsyncGetCallTrace sometimes feeds us wild frames. + // AsyncGetCallTrace interrupts the VM asynchronously. As a result + // it is possible to access an interpreter frame for which + // no Java-level information is yet available (e.g., becasue + // the frame was being created when the VM interrupted it). + // In this scenario, pretend that the interpreter is at the point + // of entering the method. + if (bci < 0) { + DEBUG_ONLY(found_bad_method_frame();) + bci = 0; + } + _mode = interpreted_mode; + _method = method; + _bci = bci; +} + +#endif // SHARE_VM_RUNTIME_VFRAME_INLINE_HPP