1/*
2 * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25#ifndef SHARE_RUNTIME_VFRAME_INLINE_HPP
26#define SHARE_RUNTIME_VFRAME_INLINE_HPP
27
28#include "runtime/frame.inline.hpp"
29#include "runtime/vframe.hpp"
30
31inline vframeStreamCommon::vframeStreamCommon(JavaThread* thread) : _reg_map(thread, false) {
32 _thread = thread;
33}
34
35inline intptr_t* vframeStreamCommon::frame_id() const { return _frame.id(); }
36
37inline bool vframeStreamCommon::is_interpreted_frame() const { return _frame.is_interpreted_frame(); }
38
39inline bool vframeStreamCommon::is_entry_frame() const { return _frame.is_entry_frame(); }
40
41inline void vframeStreamCommon::next() {
42 // handle frames with inlining
43 if (_mode == compiled_mode && fill_in_compiled_inlined_sender()) return;
44
45 // handle general case
46 do {
47 _prev_frame = _frame;
48 _frame = _frame.sender(&_reg_map);
49 } while (!fill_from_frame());
50}
51
52inline vframeStream::vframeStream(JavaThread* thread, bool stop_at_java_call_stub)
53 : vframeStreamCommon(thread) {
54 _stop_at_java_call_stub = stop_at_java_call_stub;
55
56 if (!thread->has_last_Java_frame()) {
57 _mode = at_end_mode;
58 return;
59 }
60
61 _frame = _thread->last_frame();
62 while (!fill_from_frame()) {
63 _prev_frame = _frame;
64 _frame = _frame.sender(&_reg_map);
65 }
66}
67
68inline bool vframeStreamCommon::fill_in_compiled_inlined_sender() {
69 if (_sender_decode_offset == DebugInformationRecorder::serialized_null) {
70 return false;
71 }
72 fill_from_compiled_frame(_sender_decode_offset);
73 ++_vframe_id;
74 return true;
75}
76
77
78inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {
79 _mode = compiled_mode;
80 _decode_offset = decode_offset;
81
82 // Range check to detect ridiculous offsets.
83 if (decode_offset == DebugInformationRecorder::serialized_null ||
84 decode_offset < 0 ||
85 decode_offset >= nm()->scopes_data_size()) {
86 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
87 // If we read nmethod::scopes_data at serialized_null (== 0)
88 // or if read some at other invalid offset, invalid values will be decoded.
89 // Based on these values, invalid heap locations could be referenced
90 // that could lead to crashes in product mode.
91 // Therefore, do not use the decode offset if invalid, but fill the frame
92 // as it were a native compiled frame (no Java-level assumptions).
93#ifdef ASSERT
94 if (WizardMode) {
95 ttyLocker ttyl;
96 tty->print_cr("Error in fill_from_frame: pc_desc for "
97 INTPTR_FORMAT " not found or invalid at %d",
98 p2i(_frame.pc()), decode_offset);
99 nm()->print();
100 nm()->method()->print_codes();
101 nm()->print_code();
102 nm()->print_pcs();
103 }
104 found_bad_method_frame();
105#endif
106 // Provide a cheap fallback in product mode. (See comment above.)
107 fill_from_compiled_native_frame();
108 return;
109 }
110
111 // Decode first part of scopeDesc
112 DebugInfoReadStream buffer(nm(), decode_offset);
113 _sender_decode_offset = buffer.read_int();
114 _method = buffer.read_method();
115 _bci = buffer.read_bci();
116
117 assert(_method->is_method(), "checking type of decoded method");
118}
119
120// The native frames are handled specially. We do not rely on ScopeDesc info
121// since the pc might not be exact due to the _last_native_pc trick.
122inline void vframeStreamCommon::fill_from_compiled_native_frame() {
123 _mode = compiled_mode;
124 _sender_decode_offset = DebugInformationRecorder::serialized_null;
125 _decode_offset = DebugInformationRecorder::serialized_null;
126 _vframe_id = 0;
127 _method = nm()->method();
128 _bci = 0;
129}
130
131inline bool vframeStreamCommon::fill_from_frame() {
132 // Interpreted frame
133 if (_frame.is_interpreted_frame()) {
134 fill_from_interpreter_frame();
135 return true;
136 }
137
138 // Compiled frame
139
140 if (cb() != NULL && cb()->is_compiled()) {
141 if (nm()->is_native_method()) {
142 // Do not rely on scopeDesc since the pc might be unprecise due to the _last_native_pc trick.
143 fill_from_compiled_native_frame();
144 } else {
145 PcDesc* pc_desc = nm()->pc_desc_at(_frame.pc());
146 int decode_offset;
147 if (pc_desc == NULL) {
148 // Should not happen, but let fill_from_compiled_frame handle it.
149
150 // If we are trying to walk the stack of a thread that is not
151 // at a safepoint (like AsyncGetCallTrace would do) then this is an
152 // acceptable result. [ This is assuming that safe_for_sender
153 // is so bullet proof that we can trust the frames it produced. ]
154 //
155 // So if we see that the thread is not safepoint safe
156 // then simply produce the method and a bci of zero
157 // and skip the possibility of decoding any inlining that
158 // may be present. That is far better than simply stopping (or
159 // asserting. If however the thread is safepoint safe this
160 // is the sign of a compiler bug and we'll let
161 // fill_from_compiled_frame handle it.
162
163
164 JavaThreadState state = _thread->thread_state();
165
166 // in_Java should be good enough to test safepoint safety
167 // if state were say in_Java_trans then we'd expect that
168 // the pc would have already been slightly adjusted to
169 // one that would produce a pcDesc since the trans state
170 // would be one that might in fact anticipate a safepoint
171
172 if (state == _thread_in_Java ) {
173 // This will get a method a zero bci and no inlining.
174 // Might be nice to have a unique bci to signify this
175 // particular case but for now zero will do.
176
177 fill_from_compiled_native_frame();
178
179 // There is something to be said for setting the mode to
180 // at_end_mode to prevent trying to walk further up the
181 // stack. There is evidence that if we walk any further
182 // that we could produce a bad stack chain. However until
183 // we see evidence that allowing this causes us to find
184 // frames bad enough to cause segv's or assertion failures
185 // we don't do it as while we may get a bad call chain the
186 // probability is much higher (several magnitudes) that we
187 // get good data.
188
189 return true;
190 }
191 decode_offset = DebugInformationRecorder::serialized_null;
192 } else {
193 decode_offset = pc_desc->scope_decode_offset();
194 }
195 fill_from_compiled_frame(decode_offset);
196 _vframe_id = 0;
197 }
198 return true;
199 }
200
201 // End of stack?
202 if (_frame.is_first_frame() || (_stop_at_java_call_stub && _frame.is_entry_frame())) {
203 _mode = at_end_mode;
204 return true;
205 }
206
207 return false;
208}
209
210
211inline void vframeStreamCommon::fill_from_interpreter_frame() {
212 Method* method = _frame.interpreter_frame_method();
213 address bcp = _frame.interpreter_frame_bcp();
214 int bci = method->validate_bci_from_bcp(bcp);
215 // 6379830 AsyncGetCallTrace sometimes feeds us wild frames.
216 // AsyncGetCallTrace interrupts the VM asynchronously. As a result
217 // it is possible to access an interpreter frame for which
218 // no Java-level information is yet available (e.g., becasue
219 // the frame was being created when the VM interrupted it).
220 // In this scenario, pretend that the interpreter is at the point
221 // of entering the method.
222 if (bci < 0) {
223 DEBUG_ONLY(found_bad_method_frame();)
224 bci = 0;
225 }
226 _mode = interpreted_mode;
227 _method = method;
228 _bci = bci;
229}
230
231#endif // SHARE_RUNTIME_VFRAME_INLINE_HPP
232