1 /*
2 * Copyright (c) 2015, 2017, 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.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/javaClasses.inline.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "logging/log.hpp"
30 #include "memory/oopFactory.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "oops/objArrayOop.inline.hpp"
33 #include "prims/stackwalk.hpp"
34 #include "runtime/globals.hpp"
35 #include "runtime/handles.inline.hpp"
36 #include "runtime/javaCalls.hpp"
37 #include "runtime/vframe.hpp"
38 #include "utilities/globalDefinitions.hpp"
39
40 // setup and cleanup actions
41 void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
42 frames_array->obj_at_put(magic_pos, _thread->threadObj());
43 _anchor = address_value();
44 assert(check_magic(frames_array), "invalid magic");
45 }
46
47 bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
48 oop m1 = frames_array->obj_at(magic_pos);
49 jlong m2 = _anchor;
50 if (m1 == _thread->threadObj() && m2 == address_value()) return true;
51 return false;
52 }
53
54 bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
55 bool ok = check_magic(frames_array);
56 frames_array->obj_at_put(magic_pos, NULL);
57 _anchor = 0L;
58 return ok;
59 }
60
61 JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
62 : BaseFrameStream(thread), _vfst(thread) {
63 _need_method_info = StackWalk::need_method_info(mode);
64 }
65
66 // Returns the BaseFrameStream for the current stack being traversed.
67 //
68 // Parameters:
69 // thread Current Java thread.
70 // magic Magic value used for each stack walking
71 // frames_array User-supplied buffers. The 0th element is reserved
72 // for this BaseFrameStream to use
73 //
74 BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
75 objArrayHandle frames_array)
76 {
77 assert(thread != NULL && thread->is_Java_thread(), "");
78 oop m1 = frames_array->obj_at(magic_pos);
79 if (m1 != thread->threadObj()) return NULL;
80 if (magic == 0L) return NULL;
81 BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
82 if (!stream->is_valid_in(thread, frames_array)) return NULL;
83 return stream;
84 }
85
86 // Unpacks one or more frames into user-supplied buffers.
87 // Updates the end index, and returns the number of unpacked frames.
88 // Always start with the existing vfst.method and bci.
89 // Do not call vfst.next to advance over the last returned value.
90 // In other words, do not leave any stale data in the vfst.
91 //
92 // Parameters:
93 // mode Restrict which frames to be decoded.
94 // BaseFrameStream stream of frames
95 // max_nframes Maximum number of frames to be filled.
96 // start_index Start index to the user-supplied buffers.
97 // frames_array Buffer to store Class or StackFrame in, starting at start_index.
98 // frames array is a Class<?>[] array when only getting caller
99 // reference, and a StackFrameInfo[] array (or derivative)
100 // otherwise. It should never be null.
101 // end_index End index to the user-supplied buffers with unpacked frames.
102 //
103 // Returns the number of frames whose information was transferred into the buffers.
104 //
105 int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
106 int max_nframes, int start_index,
107 objArrayHandle frames_array,
108 int& end_index, TRAPS) {
109 log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
110 max_nframes, start_index, frames_array->length());
111 assert(max_nframes > 0, "invalid max_nframes");
112 assert(start_index + max_nframes <= frames_array->length(), "oob");
113
114 int frames_decoded = 0;
115 for (; !stream.at_end(); stream.next()) {
116 Method* method = stream.method();
117
118 if (method == NULL) continue;
119
120 // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
121 // not set) and when StackWalker::getCallerClass is called
122 if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
123 if (method->is_hidden()) {
124 if (log_is_enabled(Debug, stackwalk)) {
125 ResourceMark rm(THREAD);
126 outputStream* st = Log(stackwalk)::debug_stream();
127 st->print(" hidden method: ");
128 method->print_short_name(st);
129 st->cr();
130 }
131 continue;
132 }
133 }
134
135 int index = end_index++;
136 if (log_is_enabled(Debug, stackwalk)) {
137 ResourceMark rm(THREAD);
138 outputStream* st = Log(stackwalk)::debug_stream();
139 st->print(" %d: frame method: ", index);
140 method->print_short_name(st);
141 st->print_cr(" bci=%d", stream.bci());
142 }
143
144 if (!need_method_info(mode) && get_caller_class(mode) &&
145 index == start_index && method->caller_sensitive()) {
146 ResourceMark rm(THREAD);
147 THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
148 err_msg("StackWalker::getCallerClass called from @CallerSensitive %s method",
149 method->name_and_sig_as_C_string()));
150 }
151 // fill in StackFrameInfo and initialize MemberName
152 stream.fill_frame(index, frames_array, method, CHECK_0);
153 if (++frames_decoded >= max_nframes) break;
154 }
155 return frames_decoded;
156 }
157
158 // Fill in the LiveStackFrameInfo at the given index in frames_array
159 void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array,
160 const methodHandle& method, TRAPS) {
161 Handle stackFrame(THREAD, frames_array->obj_at(index));
162 fill_live_stackframe(stackFrame, method, CHECK);
163 }
164
165 // Fill in the StackFrameInfo at the given index in frames_array
166 void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array,
167 const methodHandle& method, TRAPS) {
168 if (_need_method_info) {
169 Handle stackFrame(THREAD, frames_array->obj_at(index));
170 fill_stackframe(stackFrame, method, CHECK);
171 } else {
172 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
173 }
174 }
175
176 // Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
177 // StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
178 // T_OBJECT, or T_CONFLICT.
179 oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
180 int i, BasicType type, TRAPS) {
181 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
182 InstanceKlass* ik = InstanceKlass::cast(k);
183
184 JavaValue result(T_OBJECT);
185 JavaCallArguments args;
186 Symbol* signature = NULL;
187
188 // ## TODO: type is only available in LocalVariable table, if present.
189 // ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
190 switch (type) {
191 case T_INT:
192 args.push_int(values->int_at(i));
193 signature = vmSymbols::asPrimitive_int_signature();
194 break;
195
196 case T_LONG:
197 args.push_long(values->long_at(i));
198 signature = vmSymbols::asPrimitive_long_signature();
199 break;
200
201 case T_FLOAT:
202 case T_DOUBLE:
203 case T_BYTE:
204 case T_SHORT:
205 case T_CHAR:
206 case T_BOOLEAN:
207 THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL);
208
209 case T_OBJECT:
210 return values->obj_at(i)();
211
212 case T_CONFLICT:
213 // put a non-null slot
214 #ifdef _LP64
215 args.push_long(0);
216 signature = vmSymbols::asPrimitive_long_signature();
217 #else
218 args.push_int(0);
219 signature = vmSymbols::asPrimitive_int_signature();
220 #endif
221
222 break;
223
224 default: ShouldNotReachHere();
225 }
226 JavaCalls::call_static(&result,
227 ik,
228 vmSymbols::asPrimitive_name(),
229 signature,
230 &args,
231 CHECK_NULL);
232 return (instanceOop) result.get_jobject();
233 }
234
235 objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
236 objArrayHandle empty;
237 int length = values->size();
238 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
239 length, CHECK_(empty));
240 objArrayHandle array_h(THREAD, array_oop);
241 for (int i = 0; i < values->size(); i++) {
242 StackValue* st = values->at(i);
243 BasicType type = st->type();
244 int index = i;
245 #ifdef _LP64
246 if (type != T_OBJECT && type != T_CONFLICT) {
247 intptr_t ret = st->get_int(); // read full 64-bit slot
248 type = T_LONG; // treat as long
249 index--; // undo +1 in StackValueCollection::long_at
250 }
251 #endif
252 oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty));
253 if (obj != NULL) {
254 array_h->obj_at_put(i, obj);
255 }
256 }
257 return array_h;
258 }
259
260 objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
261 int length = monitors->length();
262 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
263 length, CHECK_(objArrayHandle()));
264 objArrayHandle array_h(THREAD, array_oop);
265 for (int i = 0; i < length; i++) {
266 MonitorInfo* monitor = monitors->at(i);
267 array_h->obj_at_put(i, monitor->owner());
268 }
269 return array_h;
270 }
271
272 // Fill StackFrameInfo with declaringClass and bci and initialize memberName
273 void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS) {
274 java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
275 java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD);
276 }
277
278 // Fill LiveStackFrameInfo with locals, monitors, and expressions
279 void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
280 const methodHandle& method, TRAPS) {
281 fill_stackframe(stackFrame, method, CHECK);
282 if (_jvf != NULL) {
283 StackValueCollection* locals = _jvf->locals();
284 StackValueCollection* expressions = _jvf->expressions();
285 GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
286
287 int mode = 0;
288 if (_jvf->is_interpreted_frame()) {
289 mode = MODE_INTERPRETED;
290 } else if (_jvf->is_compiled_frame()) {
291 mode = MODE_COMPILED;
292 }
293
294 if (!locals->is_empty()) {
295 objArrayHandle locals_h = values_to_object_array(locals, CHECK);
296 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
297 }
298 if (!expressions->is_empty()) {
299 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
300 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
301 }
302 if (monitors->length() > 0) {
303 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
304 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
305 }
306 java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
307 }
308 }
309
310 // Begins stack walking.
311 //
312 // Parameters:
313 // stackStream StackStream object
314 // mode Stack walking mode.
315 // skip_frames Number of frames to be skipped.
316 // frame_count Number of frames to be traversed.
317 // start_index Start index to the user-supplied buffers.
318 // frames_array Buffer to store StackFrame in, starting at start_index.
319 // frames array is a Class<?>[] array when only getting caller
320 // reference, and a StackFrameInfo[] array (or derivative)
321 // otherwise. It should never be null.
322 //
323 // Returns Object returned from AbstractStackWalker::doStackWalk call.
324 //
325 oop StackWalk::walk(Handle stackStream, jlong mode,
326 int skip_frames, int frame_count, int start_index,
327 objArrayHandle frames_array,
328 TRAPS) {
329 ResourceMark rm(THREAD);
330 JavaThread* jt = (JavaThread*)THREAD;
331 log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
332 mode, skip_frames, frame_count);
333
334 if (frames_array.is_null()) {
335 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
336 }
337
338 // Setup traversal onto my stack.
339 if (live_frame_info(mode)) {
340 assert (use_frames_array(mode), "Bad mode for get live frame");
341 RegisterMap regMap(jt, true);
342 LiveFrameStream stream(jt, ®Map);
343 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
344 start_index, frames_array, THREAD);
345 } else {
346 JavaFrameStream stream(jt, mode);
347 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
348 start_index, frames_array, THREAD);
349 }
350 }
351
352 oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
353 jlong mode, int skip_frames, int frame_count,
354 int start_index, objArrayHandle frames_array, TRAPS) {
355 methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
356
357 {
358 Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
359 Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
360 while (!stream.at_end()) {
361 InstanceKlass* ik = stream.method()->method_holder();
362 if (ik != stackWalker_klass &&
363 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
364 break;
365 }
366
367 if (log_is_enabled(Debug, stackwalk)) {
368 ResourceMark rm(THREAD);
369 outputStream* st = Log(stackwalk)::debug_stream();
370 st->print(" skip ");
371 stream.method()->print_short_name(st);
372 st->cr();
373 }
374 stream.next();
375 }
376
377 // stack frame has been traversed individually and resume stack walk
378 // from the stack frame at depth == skip_frames.
379 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
380 if (log_is_enabled(Debug, stackwalk)) {
381 ResourceMark rm(THREAD);
382 outputStream* st = Log(stackwalk)::debug_stream();
383 st->print(" skip ");
384 stream.method()->print_short_name(st);
385 st->cr();
386 }
387 }
388 }
389
390 int end_index = start_index;
391 int numFrames = 0;
392 if (!stream.at_end()) {
393 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
394 frames_array, end_index, CHECK_NULL);
395 if (numFrames < 1) {
396 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
397 }
398 }
399
400 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
401 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
402 // which calls the implementation to consume the stack frames.
403 // When JVM_CallStackWalk returns, it invalidates the stack stream.
404 JavaValue result(T_OBJECT);
405 JavaCallArguments args(stackStream);
406 args.push_long(stream.address_value());
407 args.push_int(skip_frames);
408 args.push_int(frame_count);
409 args.push_int(start_index);
410 args.push_int(end_index);
411
412 // Link the thread and vframe stream into the callee-visible object
413 stream.setup_magic_on_entry(frames_array);
414
415 JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
416
417 // Do this before anything else happens, to disable any lingering stream objects
418 bool ok = stream.cleanup_magic_on_exit(frames_array);
419
420 // Throw pending exception if we must
421 (void) (CHECK_NULL);
422
423 if (!ok) {
424 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
425 }
426
427 // Return normally
428 return (oop)result.get_jobject();
429 }
430
431 // Walk the next batch of stack frames
432 //
433 // Parameters:
434 // stackStream StackStream object
435 // mode Stack walking mode.
436 // magic Must be valid value to continue the stack walk
437 // frame_count Number of frames to be decoded.
438 // start_index Start index to the user-supplied buffers.
439 // frames_array Buffer to store StackFrame in, starting at start_index.
440 //
441 // Returns the end index of frame filled in the buffer.
442 //
443 jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
444 int frame_count, int start_index,
445 objArrayHandle frames_array,
446 TRAPS)
447 {
448 JavaThread* jt = (JavaThread*)THREAD;
449 BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
450 if (existing_stream == NULL) {
451 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
452 }
453
454 if (frames_array.is_null()) {
455 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
456 }
457
458 log_debug(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
459 PTR_FORMAT " start %d frames %d",
460 frame_count, p2i(existing_stream), start_index, frames_array->length());
461 int end_index = start_index;
462 if (frame_count <= 0) {
463 return end_index; // No operation.
464 }
465
466 int count = frame_count + start_index;
467 assert (frames_array->length() >= count, "not enough space in buffers");
468
469 BaseFrameStream& stream = (*existing_stream);
470 if (!stream.at_end()) {
471 stream.next(); // advance past the last frame decoded in previous batch
472 if (!stream.at_end()) {
473 int n = fill_in_frames(mode, stream, frame_count, start_index,
474 frames_array, end_index, CHECK_0);
475 if (n < 1) {
476 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
477 }
478 return end_index;
479 }
480 }
481 return end_index;
482 }