1 /*
2 * Copyright (c) 2015, 2016, 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_trace(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 {
125 ResourceMark rm;
126 outputStream* st = Log(stackwalk)::trace_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 {
137 ResourceMark rm;
138 outputStream* st = Log(stackwalk)::trace_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);
171 } else {
172 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
173 }
174 }
175
176 oop LiveFrameStream::create_primitive_value_instance(StackValueCollection* values, int i, TRAPS) {
177 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
178 instanceKlassHandle ik (THREAD, k);
179
180 JavaValue result(T_OBJECT);
181 JavaCallArguments args;
182 Symbol* signature = NULL;
183
184 // ## TODO: type is only available in LocalVariable table, if present.
185 // ## StackValue type is T_INT or T_OBJECT.
186 switch (values->at(i)->type()) {
187 case T_INT:
188 args.push_int(values->int_at(i));
189 signature = vmSymbols::asPrimitive_int_signature();
190 break;
191
192 case T_LONG:
193 args.push_long(values->long_at(i));
194 signature = vmSymbols::asPrimitive_long_signature();
195 break;
196
197 case T_FLOAT:
198 args.push_float(values->float_at(i));
199 signature = vmSymbols::asPrimitive_float_signature();
200 break;
201
202 case T_DOUBLE:
203 args.push_double(values->double_at(i));
204 signature = vmSymbols::asPrimitive_double_signature();
205 break;
206
207 case T_BYTE:
208 args.push_int(values->int_at(i));
209 signature = vmSymbols::asPrimitive_byte_signature();
210 break;
211
212 case T_SHORT:
213 args.push_int(values->int_at(i));
214 signature = vmSymbols::asPrimitive_short_signature();
215 break;
216
217 case T_CHAR:
218 args.push_int(values->int_at(i));
219 signature = vmSymbols::asPrimitive_char_signature();
220 break;
221
222 case T_BOOLEAN:
223 args.push_int(values->int_at(i));
224 signature = vmSymbols::asPrimitive_boolean_signature();
225 break;
226
227 case T_OBJECT:
228 return values->obj_at(i)();
229
230 case T_CONFLICT:
231 // put a non-null slot
232 args.push_int(0);
233 signature = vmSymbols::asPrimitive_int_signature();
234 break;
235
236 default: ShouldNotReachHere();
237 }
238 JavaCalls::call_static(&result,
239 ik,
240 vmSymbols::asPrimitive_name(),
241 signature,
242 &args,
243 CHECK_NULL);
244 return (instanceOop) result.get_jobject();
245 }
246
247 objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
248 objArrayHandle empty;
249 int length = values->size();
250 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
251 length, CHECK_(empty));
252 objArrayHandle array_h(THREAD, array_oop);
253 for (int i = 0; i < values->size(); i++) {
254 StackValue* st = values->at(i);
255 oop obj = create_primitive_value_instance(values, i, CHECK_(empty));
256 if (obj != NULL)
257 array_h->obj_at_put(i, obj);
258 }
259 return array_h;
260 }
261
262 objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
263 int length = monitors->length();
264 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
265 length, CHECK_(objArrayHandle()));
266 objArrayHandle array_h(THREAD, array_oop);
267 for (int i = 0; i < length; i++) {
268 MonitorInfo* monitor = monitors->at(i);
269 array_h->obj_at_put(i, monitor->owner());
270 }
271 return array_h;
272 }
273
274 // Fill StackFrameInfo with declaringClass and bci and initialize memberName
275 void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method) {
276 java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
277 java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci());
278 }
279
280 // Fill LiveStackFrameInfo with locals, monitors, and expressions
281 void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
282 const methodHandle& method, TRAPS) {
283 fill_stackframe(stackFrame, method);
284 if (_jvf != NULL) {
285 StackValueCollection* locals = _jvf->locals();
286 StackValueCollection* expressions = _jvf->expressions();
287 GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
288
289 if (!locals->is_empty()) {
290 objArrayHandle locals_h = values_to_object_array(locals, CHECK);
291 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
292 }
293 if (!expressions->is_empty()) {
294 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
295 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
296 }
297 if (monitors->length() > 0) {
298 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
299 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
300 }
301 }
302 }
303
304 // Begins stack walking.
305 //
306 // Parameters:
307 // stackStream StackStream object
308 // mode Stack walking mode.
309 // skip_frames Number of frames to be skipped.
310 // frame_count Number of frames to be traversed.
311 // start_index Start index to the user-supplied buffers.
312 // frames_array Buffer to store StackFrame in, starting at start_index.
313 // frames array is a Class<?>[] array when only getting caller
314 // reference, and a StackFrameInfo[] array (or derivative)
315 // otherwise. It should never be null.
316 //
317 // Returns Object returned from AbstractStackWalker::doStackWalk call.
318 //
319 oop StackWalk::walk(Handle stackStream, jlong mode,
320 int skip_frames, int frame_count, int start_index,
321 objArrayHandle frames_array,
322 TRAPS) {
323 ResourceMark rm(THREAD);
324 JavaThread* jt = (JavaThread*)THREAD;
325 log_trace(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
326 mode, skip_frames, frame_count);
327
328 if (frames_array.is_null()) {
329 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
330 }
331
332 // Setup traversal onto my stack.
333 if (live_frame_info(mode)) {
334 assert (use_frames_array(mode), "Bad mode for get live frame");
335 RegisterMap regMap(jt, true);
336 LiveFrameStream stream(jt, ®Map);
337 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
338 start_index, frames_array, THREAD);
339 } else {
340 JavaFrameStream stream(jt, mode);
341 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
342 start_index, frames_array, THREAD);
343 }
344 }
345
346 oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
347 jlong mode, int skip_frames, int frame_count,
348 int start_index, objArrayHandle frames_array, TRAPS) {
349 methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
350
351 {
352 Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
353 Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
354 while (!stream.at_end()) {
355 InstanceKlass* ik = stream.method()->method_holder();
356 if (ik != stackWalker_klass &&
357 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
358 break;
359 }
360
361 {
362 ResourceMark rm;
363 outputStream* st = Log(stackwalk)::trace_stream();
364 st->print(" skip ");
365 stream.method()->print_short_name(st);
366 st->cr();
367 }
368 stream.next();
369 }
370
371 // stack frame has been traversed individually and resume stack walk
372 // from the stack frame at depth == skip_frames.
373 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
374 ResourceMark rm;
375 outputStream* st = Log(stackwalk)::trace_stream();
376 st->print(" skip ");
377 stream.method()->print_short_name(st);
378 tty->cr();
379 }
380 }
381
382 int end_index = start_index;
383 int numFrames = 0;
384 if (!stream.at_end()) {
385 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
386 frames_array, end_index, CHECK_NULL);
387 if (numFrames < 1) {
388 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
389 }
390 }
391
392 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
393 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
394 // which calls the implementation to consume the stack frames.
395 // When JVM_CallStackWalk returns, it invalidates the stack stream.
396 JavaValue result(T_OBJECT);
397 JavaCallArguments args(stackStream);
398 args.push_long(stream.address_value());
399 args.push_int(skip_frames);
400 args.push_int(frame_count);
401 args.push_int(start_index);
402 args.push_int(end_index);
403
404 // Link the thread and vframe stream into the callee-visible object
405 stream.setup_magic_on_entry(frames_array);
406
407 JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
408
409 // Do this before anything else happens, to disable any lingering stream objects
410 bool ok = stream.cleanup_magic_on_exit(frames_array);
411
412 // Throw pending exception if we must
413 (void) (CHECK_NULL);
414
415 if (!ok) {
416 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
417 }
418
419 // Return normally
420 return (oop)result.get_jobject();
421 }
422
423 // Walk the next batch of stack frames
424 //
425 // Parameters:
426 // stackStream StackStream object
427 // mode Stack walking mode.
428 // magic Must be valid value to continue the stack walk
429 // frame_count Number of frames to be decoded.
430 // start_index Start index to the user-supplied buffers.
431 // frames_array Buffer to store StackFrame in, starting at start_index.
432 //
433 // Returns the end index of frame filled in the buffer.
434 //
435 jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
436 int frame_count, int start_index,
437 objArrayHandle frames_array,
438 TRAPS)
439 {
440 JavaThread* jt = (JavaThread*)THREAD;
441 BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
442 if (existing_stream == NULL) {
443 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
444 }
445
446 if (frames_array.is_null()) {
447 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
448 }
449
450 log_trace(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
451 PTR_FORMAT " start %d frames %d",
452 frame_count,
453 p2i(existing_stream),
454 start_index,
455 frames_array->length());
456 int end_index = start_index;
457 if (frame_count <= 0) {
458 return end_index; // No operation.
459 }
460
461 int count = frame_count + start_index;
462 assert (frames_array->length() >= count, "not enough space in buffers");
463
464 BaseFrameStream& stream = (*existing_stream);
465 if (!stream.at_end()) {
466 stream.next(); // advance past the last frame decoded in previous batch
467 if (!stream.at_end()) {
468 int n = fill_in_frames(mode, stream, frame_count, start_index,
469 frames_array, end_index, CHECK_0);
470 if (n < 1) {
471 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
472 }
473 return end_index;
474 }
475 }
476 return end_index;
477 }