1 /*
2 * Copyright (c) 2015, 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.
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 "logging/logStream.hpp"
31 #include "memory/oopFactory.hpp"
32 #include "memory/universe.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "oops/objArrayOop.inline.hpp"
35 #include "prims/stackwalk.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/javaCalls.hpp"
39 #include "runtime/thread.inline.hpp"
40 #include "runtime/vframe.inline.hpp"
41 #include "utilities/globalDefinitions.hpp"
42
43 // setup and cleanup actions
44 void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
45 frames_array->obj_at_put(magic_pos, _thread->threadObj());
46 _anchor = address_value();
47 assert(check_magic(frames_array), "invalid magic");
48 }
49
50 bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
51 oop m1 = frames_array->obj_at(magic_pos);
52 jlong m2 = _anchor;
53 if (m1 == _thread->threadObj() && m2 == address_value()) return true;
54 return false;
55 }
56
57 bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
58 bool ok = check_magic(frames_array);
59 frames_array->obj_at_put(magic_pos, NULL);
60 _anchor = 0L;
61 return ok;
62 }
63
64 JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
65 : BaseFrameStream(thread), _vfst(thread) {
66 _need_method_info = StackWalk::need_method_info(mode);
67 }
68
69 void JavaFrameStream::next() { _vfst.next();}
70
71 // Returns the BaseFrameStream for the current stack being traversed.
72 //
73 // Parameters:
74 // thread Current Java thread.
75 // magic Magic value used for each stack walking
76 // frames_array User-supplied buffers. The 0th element is reserved
77 // for this BaseFrameStream to use
78 //
79 BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
80 objArrayHandle frames_array)
81 {
82 assert(thread != NULL && thread->is_Java_thread(), "");
83 oop m1 = frames_array->obj_at(magic_pos);
84 if (m1 != thread->threadObj()) return NULL;
85 if (magic == 0L) return NULL;
86 BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
87 if (!stream->is_valid_in(thread, frames_array)) return NULL;
88 return stream;
89 }
90
91 // Unpacks one or more frames into user-supplied buffers.
92 // Updates the end index, and returns the number of unpacked frames.
93 // Always start with the existing vfst.method and bci.
94 // Do not call vfst.next to advance over the last returned value.
95 // In other words, do not leave any stale data in the vfst.
96 //
97 // Parameters:
98 // mode Restrict which frames to be decoded.
99 // BaseFrameStream stream of frames
100 // max_nframes Maximum number of frames to be filled.
101 // start_index Start index to the user-supplied buffers.
102 // frames_array Buffer to store Class or StackFrame in, starting at start_index.
103 // frames array is a Class<?>[] array when only getting caller
104 // reference, and a StackFrameInfo[] array (or derivative)
105 // otherwise. It should never be null.
106 // end_index End index to the user-supplied buffers with unpacked frames.
107 //
108 // Returns the number of frames whose information was transferred into the buffers.
109 //
110 int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
111 int max_nframes, int start_index,
112 objArrayHandle frames_array,
113 int& end_index, TRAPS) {
114 log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
115 max_nframes, start_index, frames_array->length());
116 assert(max_nframes > 0, "invalid max_nframes");
117 assert(start_index + max_nframes <= frames_array->length(), "oob");
118
119 int frames_decoded = 0;
120 for (; !stream.at_end(); stream.next()) {
121 Method* method = stream.method();
122
123 if (method == NULL) continue;
124
125 // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
126 // not set) and when StackWalker::getCallerClass is called
127 if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
128 if (method->is_hidden()) {
129 LogTarget(Debug, stackwalk) lt;
130 if (lt.is_enabled()) {
131 ResourceMark rm(THREAD);
132 LogStream ls(lt);
133 ls.print(" hidden method: ");
134 method->print_short_name(&ls);
135 ls.cr();
136 }
137 continue;
138 }
139 }
140
141 int index = end_index++;
142 LogTarget(Debug, stackwalk) lt;
143 if (lt.is_enabled()) {
144 ResourceMark rm(THREAD);
145 LogStream ls(lt);
146 ls.print(" %d: frame method: ", index);
147 method->print_short_name(&ls);
148 ls.print_cr(" bci=%d", stream.bci());
149 }
150
151 if (!need_method_info(mode) && get_caller_class(mode) &&
152 index == start_index && method->caller_sensitive()) {
153 ResourceMark rm(THREAD);
154 THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
155 err_msg("StackWalker::getCallerClass called from @CallerSensitive '%s' method",
156 method->external_name()));
157 }
158 // fill in StackFrameInfo and initialize MemberName
159 stream.fill_frame(index, frames_array, method, CHECK_0);
160 if (++frames_decoded >= max_nframes) break;
161 }
162 return frames_decoded;
163 }
164
165 // Fill in the LiveStackFrameInfo at the given index in frames_array
166 void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array,
167 const methodHandle& method, TRAPS) {
168 HandleMark hm(THREAD);
169 Handle stackFrame(THREAD, frames_array->obj_at(index));
170 fill_live_stackframe(stackFrame, method, CHECK);
171 }
172
173 // Fill in the StackFrameInfo at the given index in frames_array
174 void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array,
175 const methodHandle& method, TRAPS) {
176 if (_need_method_info) {
177 HandleMark hm(THREAD);
178 Handle stackFrame(THREAD, frames_array->obj_at(index));
179 fill_stackframe(stackFrame, method, CHECK);
180 } else {
181 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
182 }
183 }
184
185 // Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
186 // StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
187 // T_OBJECT, or T_CONFLICT.
188 oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
189 int i, BasicType type, TRAPS) {
190 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
191 InstanceKlass* ik = InstanceKlass::cast(k);
192
193 JavaValue result(T_OBJECT);
194 JavaCallArguments args;
195 Symbol* signature = NULL;
196
197 // ## TODO: type is only available in LocalVariable table, if present.
198 // ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
199 switch (type) {
200 case T_INT:
201 args.push_int(values->int_at(i));
202 signature = vmSymbols::asPrimitive_int_signature();
203 break;
204
205 case T_LONG:
206 args.push_long(values->long_at(i));
207 signature = vmSymbols::asPrimitive_long_signature();
208 break;
209
210 case T_FLOAT:
211 case T_DOUBLE:
212 case T_BYTE:
213 case T_SHORT:
214 case T_CHAR:
215 case T_BOOLEAN:
216 THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL);
217
218 case T_OBJECT:
219 return values->obj_at(i)();
220
221 case T_CONFLICT:
222 // put a non-null slot
223 #ifdef _LP64
224 args.push_long(0);
225 signature = vmSymbols::asPrimitive_long_signature();
226 #else
227 args.push_int(0);
228 signature = vmSymbols::asPrimitive_int_signature();
229 #endif
230
231 break;
232
233 default: ShouldNotReachHere();
234 }
235 JavaCalls::call_static(&result,
236 ik,
237 vmSymbols::asPrimitive_name(),
238 signature,
239 &args,
240 CHECK_NULL);
241 return (instanceOop) result.get_jobject();
242 }
243
244 objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
245 objArrayHandle empty;
246 int length = values->size();
247 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
248 length, CHECK_(empty));
249 objArrayHandle array_h(THREAD, array_oop);
250 for (int i = 0; i < values->size(); i++) {
251 StackValue* st = values->at(i);
252 BasicType type = st->type();
253 int index = i;
254 #ifdef _LP64
255 if (type != T_OBJECT && type != T_CONFLICT) {
256 intptr_t ret = st->get_int(); // read full 64-bit slot
257 type = T_LONG; // treat as long
258 index--; // undo +1 in StackValueCollection::long_at
259 }
260 #endif
261 oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty));
262 if (obj != NULL) {
263 array_h->obj_at_put(i, obj);
264 }
265 }
266 return array_h;
267 }
268
269 objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
270 int length = monitors->length();
271 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
272 length, CHECK_(objArrayHandle()));
273 objArrayHandle array_h(THREAD, array_oop);
274 for (int i = 0; i < length; i++) {
275 MonitorInfo* monitor = monitors->at(i);
276 array_h->obj_at_put(i, monitor->owner());
277 }
278 return array_h;
279 }
280
281 // Fill StackFrameInfo with bci and initialize memberName
282 void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS) {
283 java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD);
284 }
285
286 // Fill LiveStackFrameInfo with locals, monitors, and expressions
287 void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
288 const methodHandle& method, TRAPS) {
289 fill_stackframe(stackFrame, method, CHECK);
290 if (_jvf != NULL) {
291 StackValueCollection* locals = _jvf->locals();
292 StackValueCollection* expressions = _jvf->expressions();
293 GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
294
295 int mode = 0;
296 if (_jvf->is_interpreted_frame()) {
297 mode = MODE_INTERPRETED;
298 } else if (_jvf->is_compiled_frame()) {
299 mode = MODE_COMPILED;
300 }
301
302 if (!locals->is_empty()) {
303 objArrayHandle locals_h = values_to_object_array(locals, CHECK);
304 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
305 }
306 if (!expressions->is_empty()) {
307 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
308 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
309 }
310 if (monitors->length() > 0) {
311 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
312 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
313 }
314 java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
315 }
316 }
317
318 // Begins stack walking.
319 //
320 // Parameters:
321 // stackStream StackStream object
322 // mode Stack walking mode.
323 // skip_frames Number of frames to be skipped.
324 // frame_count Number of frames to be traversed.
325 // start_index Start index to the user-supplied buffers.
326 // frames_array Buffer to store StackFrame in, starting at start_index.
327 // frames array is a Class<?>[] array when only getting caller
328 // reference, and a StackFrameInfo[] array (or derivative)
329 // otherwise. It should never be null.
330 //
331 // Returns Object returned from AbstractStackWalker::doStackWalk call.
332 //
333 oop StackWalk::walk(Handle stackStream, jlong mode,
334 int skip_frames, int frame_count, int start_index,
335 objArrayHandle frames_array,
336 TRAPS) {
337 ResourceMark rm(THREAD);
338 JavaThread* jt = (JavaThread*)THREAD;
339 log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
340 mode, skip_frames, frame_count);
341
342 if (frames_array.is_null()) {
343 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
344 }
345
346 // Setup traversal onto my stack.
347 if (live_frame_info(mode)) {
348 assert (use_frames_array(mode), "Bad mode for get live frame");
349 RegisterMap regMap(jt, true);
350 LiveFrameStream stream(jt, ®Map);
351 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
352 start_index, frames_array, THREAD);
353 } else {
354 JavaFrameStream stream(jt, mode);
355 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
356 start_index, frames_array, THREAD);
357 }
358 }
359
360 oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
361 jlong mode, int skip_frames, int frame_count,
362 int start_index, objArrayHandle frames_array, TRAPS) {
363 methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
364
365 {
366 Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
367 Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
368 while (!stream.at_end()) {
369 InstanceKlass* ik = stream.method()->method_holder();
370 if (ik != stackWalker_klass &&
371 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
372 break;
373 }
374
375 LogTarget(Debug, stackwalk) lt;
376 if (lt.is_enabled()) {
377 ResourceMark rm(THREAD);
378 LogStream ls(lt);
379 ls.print(" skip ");
380 stream.method()->print_short_name(&ls);
381 ls.cr();
382 }
383 stream.next();
384 }
385
386 // stack frame has been traversed individually and resume stack walk
387 // from the stack frame at depth == skip_frames.
388 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
389 LogTarget(Debug, stackwalk) lt;
390 if (lt.is_enabled()) {
391 ResourceMark rm(THREAD);
392 LogStream ls(lt);
393 ls.print(" skip ");
394 stream.method()->print_short_name(&ls);
395 ls.cr();
396 }
397 }
398 }
399
400 int end_index = start_index;
401 int numFrames = 0;
402 if (!stream.at_end()) {
403 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
404 frames_array, end_index, CHECK_NULL);
405 if (numFrames < 1) {
406 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
407 }
408 }
409
410 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
411 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
412 // which calls the implementation to consume the stack frames.
413 // When JVM_CallStackWalk returns, it invalidates the stack stream.
414 JavaValue result(T_OBJECT);
415 JavaCallArguments args(stackStream);
416 args.push_long(stream.address_value());
417 args.push_int(skip_frames);
418 args.push_int(frame_count);
419 args.push_int(start_index);
420 args.push_int(end_index);
421
422 // Link the thread and vframe stream into the callee-visible object
423 stream.setup_magic_on_entry(frames_array);
424
425 JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
426
427 // Do this before anything else happens, to disable any lingering stream objects
428 bool ok = stream.cleanup_magic_on_exit(frames_array);
429
430 // Throw pending exception if we must
431 (void) (CHECK_NULL);
432
433 if (!ok) {
434 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
435 }
436
437 // Return normally
438 return (oop)result.get_jobject();
439 }
440
441 // Walk the next batch of stack frames
442 //
443 // Parameters:
444 // stackStream StackStream object
445 // mode Stack walking mode.
446 // magic Must be valid value to continue the stack walk
447 // frame_count Number of frames to be decoded.
448 // start_index Start index to the user-supplied buffers.
449 // frames_array Buffer to store StackFrame in, starting at start_index.
450 //
451 // Returns the end index of frame filled in the buffer.
452 //
453 jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
454 int frame_count, int start_index,
455 objArrayHandle frames_array,
456 TRAPS)
457 {
458 JavaThread* jt = (JavaThread*)THREAD;
459 BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
460 if (existing_stream == NULL) {
461 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
462 }
463
464 if (frames_array.is_null()) {
465 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
466 }
467
468 log_debug(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
469 PTR_FORMAT " start %d frames %d",
470 frame_count, p2i(existing_stream), start_index, frames_array->length());
471 int end_index = start_index;
472 if (frame_count <= 0) {
473 return end_index; // No operation.
474 }
475
476 int count = frame_count + start_index;
477 assert (frames_array->length() >= count, "not enough space in buffers");
478
479 BaseFrameStream& stream = (*existing_stream);
480 if (!stream.at_end()) {
481 stream.next(); // advance past the last frame decoded in previous batch
482 if (!stream.at_end()) {
483 int n = fill_in_frames(mode, stream, frame_count, start_index,
484 frames_array, end_index, CHECK_0);
485 if (n < 1) {
486 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
487 }
488 return end_index;
489 }
490 }
491 return end_index;
492 }