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