1 /*
2 * Copyright (c) 2015, 2018, 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 "oops/oop.inline.hpp"
33 #include "oops/objArrayOop.inline.hpp"
34 #include "prims/stackwalk.hpp"
35 #include "runtime/globals.hpp"
36 #include "runtime/handles.inline.hpp"
37 #include "runtime/javaCalls.hpp"
38 #include "runtime/vframe.inline.hpp"
39 #include "utilities/globalDefinitions.hpp"
40
41 // setup and cleanup actions
42 void BaseFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
43 frames_array->obj_at_put(magic_pos, _thread->threadObj());
44 _anchor = address_value();
45 assert(check_magic(frames_array), "invalid magic");
46 }
47
48 bool BaseFrameStream::check_magic(objArrayHandle frames_array) {
49 oop m1 = frames_array->obj_at(magic_pos);
50 jlong m2 = _anchor;
51 if (oopDesc::equals(m1, _thread->threadObj()) && m2 == address_value()) return true;
52 return false;
53 }
54
55 bool BaseFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
56 bool ok = check_magic(frames_array);
57 frames_array->obj_at_put(magic_pos, NULL);
58 _anchor = 0L;
59 return ok;
60 }
61
62 JavaFrameStream::JavaFrameStream(JavaThread* thread, int mode)
63 : BaseFrameStream(thread), _vfst(thread) {
64 _need_method_info = StackWalk::need_method_info(mode);
65 }
66
67 void JavaFrameStream::next() { _vfst.next();}
68
69 // Returns the BaseFrameStream for the current stack being traversed.
70 //
71 // Parameters:
72 // thread Current Java thread.
73 // magic Magic value used for each stack walking
74 // frames_array User-supplied buffers. The 0th element is reserved
75 // for this BaseFrameStream to use
76 //
77 BaseFrameStream* BaseFrameStream::from_current(JavaThread* thread, jlong magic,
78 objArrayHandle frames_array)
79 {
80 assert(thread != NULL && thread->is_Java_thread(), "");
81 oop m1 = frames_array->obj_at(magic_pos);
82 if (!oopDesc::equals(m1, thread->threadObj())) return NULL;
83 if (magic == 0L) return NULL;
84 BaseFrameStream* stream = (BaseFrameStream*) (intptr_t) magic;
85 if (!stream->is_valid_in(thread, frames_array)) return NULL;
86 return stream;
87 }
88
89 // Unpacks one or more frames into user-supplied buffers.
90 // Updates the end index, and returns the number of unpacked frames.
91 // Always start with the existing vfst.method and bci.
92 // Do not call vfst.next to advance over the last returned value.
93 // In other words, do not leave any stale data in the vfst.
94 //
95 // Parameters:
96 // mode Restrict which frames to be decoded.
97 // BaseFrameStream stream of frames
98 // max_nframes Maximum number of frames to be filled.
99 // start_index Start index to the user-supplied buffers.
100 // frames_array Buffer to store Class or StackFrame in, starting at start_index.
101 // frames array is a Class<?>[] array when only getting caller
102 // reference, and a StackFrameInfo[] array (or derivative)
103 // otherwise. It should never be null.
104 // end_index End index to the user-supplied buffers with unpacked frames.
105 //
106 // Returns the number of frames whose information was transferred into the buffers.
107 //
108 int StackWalk::fill_in_frames(jlong mode, BaseFrameStream& stream,
109 int max_nframes, int start_index,
110 objArrayHandle frames_array,
111 int& end_index, TRAPS) {
112 log_debug(stackwalk)("fill_in_frames limit=%d start=%d frames length=%d",
113 max_nframes, start_index, frames_array->length());
114 assert(max_nframes > 0, "invalid max_nframes");
115 assert(start_index + max_nframes <= frames_array->length(), "oob");
116
117 int frames_decoded = 0;
118 for (; !stream.at_end(); stream.next()) {
119 Method* method = stream.method();
120
121 if (method == NULL) continue;
122
123 // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
124 // not set) and when StackWalker::getCallerClass is called
125 if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
126 if (method->is_hidden()) {
127 LogTarget(Debug, stackwalk) lt;
128 if (lt.is_enabled()) {
129 ResourceMark rm(THREAD);
130 LogStream ls(lt);
131 ls.print(" hidden method: ");
132 method->print_short_name(&ls);
133 ls.cr();
134 }
135 continue;
136 }
137 }
138
139 int index = end_index++;
140 LogTarget(Debug, stackwalk) lt;
141 if (lt.is_enabled()) {
142 ResourceMark rm(THREAD);
143 LogStream ls(lt);
144 ls.print(" %d: frame method: ", index);
145 method->print_short_name(&ls);
146 ls.print_cr(" bci=%d", stream.bci());
147 }
148
149 if (!need_method_info(mode) && get_caller_class(mode) &&
150 index == start_index && method->caller_sensitive()) {
151 ResourceMark rm(THREAD);
152 THROW_MSG_0(vmSymbols::java_lang_UnsupportedOperationException(),
153 err_msg("StackWalker::getCallerClass called from @CallerSensitive %s method",
154 method->name_and_sig_as_C_string()));
155 }
156 // fill in StackFrameInfo and initialize MemberName
157 stream.fill_frame(index, frames_array, method, CHECK_0);
158 if (++frames_decoded >= max_nframes) break;
159 }
160 return frames_decoded;
161 }
162
163 // Fill in the LiveStackFrameInfo at the given index in frames_array
164 void LiveFrameStream::fill_frame(int index, objArrayHandle frames_array,
165 const methodHandle& method, TRAPS) {
166 Handle stackFrame(THREAD, frames_array->obj_at(index));
167 fill_live_stackframe(stackFrame, method, CHECK);
168 }
169
170 // Fill in the StackFrameInfo at the given index in frames_array
171 void JavaFrameStream::fill_frame(int index, objArrayHandle frames_array,
172 const methodHandle& method, TRAPS) {
173 if (_need_method_info) {
174 Handle stackFrame(THREAD, frames_array->obj_at(index));
175 fill_stackframe(stackFrame, method, CHECK);
176 } else {
177 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
178 }
179 }
180
181 // Create and return a LiveStackFrame.PrimitiveSlot (if needed) for the
182 // StackValue at the given index. 'type' is expected to be T_INT, T_LONG,
183 // T_OBJECT, or T_CONFLICT.
184 oop LiveFrameStream::create_primitive_slot_instance(StackValueCollection* values,
185 int i, BasicType type, TRAPS) {
186 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
187 InstanceKlass* ik = InstanceKlass::cast(k);
188
189 JavaValue result(T_OBJECT);
190 JavaCallArguments args;
191 Symbol* signature = NULL;
192
193 // ## TODO: type is only available in LocalVariable table, if present.
194 // ## StackValue type is T_INT or T_OBJECT (or converted to T_LONG on 64-bit)
195 switch (type) {
196 case T_INT:
197 args.push_int(values->int_at(i));
198 signature = vmSymbols::asPrimitive_int_signature();
199 break;
200
201 case T_LONG:
202 args.push_long(values->long_at(i));
203 signature = vmSymbols::asPrimitive_long_signature();
204 break;
205
206 case T_FLOAT:
207 case T_DOUBLE:
208 case T_BYTE:
209 case T_SHORT:
210 case T_CHAR:
211 case T_BOOLEAN:
212 THROW_MSG_(vmSymbols::java_lang_InternalError(), "Unexpected StackValue type", NULL);
213
214 case T_OBJECT:
215 return values->obj_at(i)();
216
217 case T_CONFLICT:
218 // put a non-null slot
219 #ifdef _LP64
220 args.push_long(0);
221 signature = vmSymbols::asPrimitive_long_signature();
222 #else
223 args.push_int(0);
224 signature = vmSymbols::asPrimitive_int_signature();
225 #endif
226
227 break;
228
229 default: ShouldNotReachHere();
230 }
231 JavaCalls::call_static(&result,
232 ik,
233 vmSymbols::asPrimitive_name(),
234 signature,
235 &args,
236 CHECK_NULL);
237 return (instanceOop) result.get_jobject();
238 }
239
240 objArrayHandle LiveFrameStream::values_to_object_array(StackValueCollection* values, TRAPS) {
241 objArrayHandle empty;
242 int length = values->size();
243 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
244 length, CHECK_(empty));
245 objArrayHandle array_h(THREAD, array_oop);
246 for (int i = 0; i < values->size(); i++) {
247 StackValue* st = values->at(i);
248 BasicType type = st->type();
249 int index = i;
250 #ifdef _LP64
251 if (type != T_OBJECT && type != T_CONFLICT) {
252 intptr_t ret = st->get_int(); // read full 64-bit slot
253 type = T_LONG; // treat as long
254 index--; // undo +1 in StackValueCollection::long_at
255 }
256 #endif
257 oop obj = create_primitive_slot_instance(values, index, type, CHECK_(empty));
258 if (obj != NULL) {
259 array_h->obj_at_put(i, obj);
260 }
261 }
262 return array_h;
263 }
264
265 objArrayHandle LiveFrameStream::monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
266 int length = monitors->length();
267 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
268 length, CHECK_(objArrayHandle()));
269 objArrayHandle array_h(THREAD, array_oop);
270 for (int i = 0; i < length; i++) {
271 MonitorInfo* monitor = monitors->at(i);
272 array_h->obj_at_put(i, monitor->owner());
273 }
274 return array_h;
275 }
276
277 // Fill StackFrameInfo with bci and initialize memberName
278 void BaseFrameStream::fill_stackframe(Handle stackFrame, const methodHandle& method, TRAPS) {
279 java_lang_StackFrameInfo::set_method_and_bci(stackFrame, method, bci(), THREAD);
280 }
281
282 // Fill LiveStackFrameInfo with locals, monitors, and expressions
283 void LiveFrameStream::fill_live_stackframe(Handle stackFrame,
284 const methodHandle& method, TRAPS) {
285 fill_stackframe(stackFrame, method, CHECK);
286 if (_jvf != NULL) {
287 StackValueCollection* locals = _jvf->locals();
288 StackValueCollection* expressions = _jvf->expressions();
289 GrowableArray<MonitorInfo*>* monitors = _jvf->monitors();
290
291 int mode = 0;
292 if (_jvf->is_interpreted_frame()) {
293 mode = MODE_INTERPRETED;
294 } else if (_jvf->is_compiled_frame()) {
295 mode = MODE_COMPILED;
296 }
297
298 if (!locals->is_empty()) {
299 objArrayHandle locals_h = values_to_object_array(locals, CHECK);
300 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
301 }
302 if (!expressions->is_empty()) {
303 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
304 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
305 }
306 if (monitors->length() > 0) {
307 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
308 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
309 }
310 java_lang_LiveStackFrameInfo::set_mode(stackFrame(), mode);
311 }
312 }
313
314 // Begins stack walking.
315 //
316 // Parameters:
317 // stackStream StackStream object
318 // mode Stack walking mode.
319 // skip_frames Number of frames to be skipped.
320 // frame_count Number of frames to be traversed.
321 // start_index Start index to the user-supplied buffers.
322 // frames_array Buffer to store StackFrame in, starting at start_index.
323 // frames array is a Class<?>[] array when only getting caller
324 // reference, and a StackFrameInfo[] array (or derivative)
325 // otherwise. It should never be null.
326 //
327 // Returns Object returned from AbstractStackWalker::doStackWalk call.
328 //
329 oop StackWalk::walk(Handle stackStream, jlong mode,
330 int skip_frames, int frame_count, int start_index,
331 objArrayHandle frames_array,
332 TRAPS) {
333 ResourceMark rm(THREAD);
334 JavaThread* jt = (JavaThread*)THREAD;
335 log_debug(stackwalk)("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
336 mode, skip_frames, frame_count);
337
338 if (frames_array.is_null()) {
339 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
340 }
341
342 // Setup traversal onto my stack.
343 if (live_frame_info(mode)) {
344 assert (use_frames_array(mode), "Bad mode for get live frame");
345 RegisterMap regMap(jt, true);
346 LiveFrameStream stream(jt, ®Map);
347 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
348 start_index, frames_array, THREAD);
349 } else {
350 JavaFrameStream stream(jt, mode);
351 return fetchFirstBatch(stream, stackStream, mode, skip_frames, frame_count,
352 start_index, frames_array, THREAD);
353 }
354 }
355
356 oop StackWalk::fetchFirstBatch(BaseFrameStream& stream, Handle stackStream,
357 jlong mode, int skip_frames, int frame_count,
358 int start_index, objArrayHandle frames_array, TRAPS) {
359 methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
360
361 {
362 Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
363 Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
364 while (!stream.at_end()) {
365 InstanceKlass* ik = stream.method()->method_holder();
366 if (ik != stackWalker_klass &&
367 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
368 break;
369 }
370
371 LogTarget(Debug, stackwalk) lt;
372 if (lt.is_enabled()) {
373 ResourceMark rm(THREAD);
374 LogStream ls(lt);
375 ls.print(" skip ");
376 stream.method()->print_short_name(&ls);
377 ls.cr();
378 }
379 stream.next();
380 }
381
382 // stack frame has been traversed individually and resume stack walk
383 // from the stack frame at depth == skip_frames.
384 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
385 LogTarget(Debug, stackwalk) lt;
386 if (lt.is_enabled()) {
387 ResourceMark rm(THREAD);
388 LogStream ls(lt);
389 ls.print(" skip ");
390 stream.method()->print_short_name(&ls);
391 ls.cr();
392 }
393 }
394 }
395
396 int end_index = start_index;
397 int numFrames = 0;
398 if (!stream.at_end()) {
399 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
400 frames_array, end_index, CHECK_NULL);
401 if (numFrames < 1) {
402 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
403 }
404 }
405
406 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
407 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
408 // which calls the implementation to consume the stack frames.
409 // When JVM_CallStackWalk returns, it invalidates the stack stream.
410 JavaValue result(T_OBJECT);
411 JavaCallArguments args(stackStream);
412 args.push_long(stream.address_value());
413 args.push_int(skip_frames);
414 args.push_int(frame_count);
415 args.push_int(start_index);
416 args.push_int(end_index);
417
418 // Link the thread and vframe stream into the callee-visible object
419 stream.setup_magic_on_entry(frames_array);
420
421 JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
422
423 // Do this before anything else happens, to disable any lingering stream objects
424 bool ok = stream.cleanup_magic_on_exit(frames_array);
425
426 // Throw pending exception if we must
427 (void) (CHECK_NULL);
428
429 if (!ok) {
430 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
431 }
432
433 // Return normally
434 return (oop)result.get_jobject();
435 }
436
437 // Walk the next batch of stack frames
438 //
439 // Parameters:
440 // stackStream StackStream object
441 // mode Stack walking mode.
442 // magic Must be valid value to continue the stack walk
443 // frame_count Number of frames to be decoded.
444 // start_index Start index to the user-supplied buffers.
445 // frames_array Buffer to store StackFrame in, starting at start_index.
446 //
447 // Returns the end index of frame filled in the buffer.
448 //
449 jint StackWalk::fetchNextBatch(Handle stackStream, jlong mode, jlong magic,
450 int frame_count, int start_index,
451 objArrayHandle frames_array,
452 TRAPS)
453 {
454 JavaThread* jt = (JavaThread*)THREAD;
455 BaseFrameStream* existing_stream = BaseFrameStream::from_current(jt, magic, frames_array);
456 if (existing_stream == NULL) {
457 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
458 }
459
460 if (frames_array.is_null()) {
461 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
462 }
463
464 log_debug(stackwalk)("StackWalk::fetchNextBatch frame_count %d existing_stream "
465 PTR_FORMAT " start %d frames %d",
466 frame_count, p2i(existing_stream), start_index, frames_array->length());
467 int end_index = start_index;
468 if (frame_count <= 0) {
469 return end_index; // No operation.
470 }
471
472 int count = frame_count + start_index;
473 assert (frames_array->length() >= count, "not enough space in buffers");
474
475 BaseFrameStream& stream = (*existing_stream);
476 if (!stream.at_end()) {
477 stream.next(); // advance past the last frame decoded in previous batch
478 if (!stream.at_end()) {
479 int n = fill_in_frames(mode, stream, frame_count, start_index,
480 frames_array, end_index, CHECK_0);
481 if (n < 1) {
482 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
483 }
484 return end_index;
485 }
486 }
487 return end_index;
488 }