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 "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 JavaFrameStream::setup_magic_on_entry(objArrayHandle frames_array) {
41 frames_array->obj_at_put(magic_pos, _thread->threadObj());
42 _anchor = address_value();
43 assert(check_magic(frames_array), "invalid magic");
44 }
45
46 bool JavaFrameStream::check_magic(objArrayHandle frames_array) {
47 oop m1 = frames_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 JavaFrameStream::cleanup_magic_on_exit(objArrayHandle frames_array) {
54 bool ok = check_magic(frames_array);
55 frames_array->obj_at_put(magic_pos, NULL);
56 _anchor = 0L;
57 return ok;
58 }
59
60 // Returns JavaFrameStream for the current stack being traversed.
61 //
62 // Parameters:
63 // thread Current Java thread.
64 // magic Magic value used for each stack walking
65 // frames_array User-supplied buffers. The 0th element is reserved
66 // to this JavaFrameStream to use
67 //
68 JavaFrameStream* JavaFrameStream::from_current(JavaThread* thread, jlong magic,
69 objArrayHandle frames_array)
70 {
71 assert(thread != NULL && thread->is_Java_thread(), "");
72 oop m1 = frames_array->obj_at(magic_pos);
73 if (m1 != thread->threadObj()) return NULL;
74 if (magic == 0L) return NULL;
75 JavaFrameStream* stream = (JavaFrameStream*) (intptr_t) magic;
76 if (!stream->is_valid_in(thread, frames_array)) return NULL;
77 return stream;
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 // JavaFrameStream stream of javaVFrames
89 // max_nframes Maximum number of frames to be filled.
90 // start_index Start index to the user-supplied buffers.
91 // frames_array Buffer to store Class or StackFrame in, starting at start_index.
92 // frames array is a Class<?>[] array when only getting caller
93 // reference, and a StackFrameInfo[] array (or derivative)
94 // otherwise. It should never be null.
95 // end_index End index to the user-supplied buffers with unpacked frames.
96 //
97 // Returns the number of frames whose information was transferred into the buffers.
98 //
99 int StackWalk::fill_in_frames(jlong mode, JavaFrameStream& stream,
100 int max_nframes, int start_index,
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, frames_array->length());
106 }
107 assert(max_nframes > 0, "invalid max_nframes");
108 assert(start_index + max_nframes <= frames_array->length(), "oob");
109
110 int frames_decoded = 0;
111 for (; !stream.at_end(); stream.next()) {
112 Method* method = stream.method();
113 int bci = stream.bci();
114
115 if (method == NULL) continue;
116
117 // skip hidden frames for default StackWalker option (i.e. SHOW_HIDDEN_FRAMES
118 // not set) and when StackWalker::getCallerClass is called
119 if (!ShowHiddenFrames && (skip_hidden_frames(mode) || get_caller_class(mode))) {
120 if (method->is_hidden()) {
121 if (TraceStackWalk) {
122 tty->print(" hidden method: "); method->print_short_name();
123 tty->print("\n");
124 }
125 continue;
126 }
127 }
128
129 int index = end_index++;
130 if (TraceStackWalk) {
131 tty->print(" %d: frame method: ", index); method->print_short_name();
132 tty->print_cr(" bci=%d", bci);
133 }
134
135 // fill in StackFrameInfo and initialize MemberName
136 if (live_frame_info(mode)) {
137 assert (use_frames_array(mode), "Bad mode for get live frame");
138 Handle stackFrame(frames_array->obj_at(index));
139 fill_live_stackframe(stackFrame, method, bci, stream.java_frame(), CHECK_0);
140 } else if (need_method_info(mode)) {
141 assert (use_frames_array(mode), "Bad mode for get stack frame");
142 Handle stackFrame(frames_array->obj_at(index));
143 fill_stackframe(stackFrame, method, bci);
144 } else {
145 assert (get_caller_class(mode) == true, "Bad mode for get caller class");
146 if (index == start_index && method->caller_sensitive()) {
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
152 frames_array->obj_at_put(index, method->method_holder()->java_mirror());
153 }
154 if (++frames_decoded >= max_nframes) break;
155 }
156 return frames_decoded;
157 }
158
159 static oop create_primitive_value_instance(StackValueCollection* values, int i, TRAPS) {
160 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::java_lang_LiveStackFrameInfo(), CHECK_NULL);
161 instanceKlassHandle ik (THREAD, k);
162
163 JavaValue result(T_OBJECT);
164 JavaCallArguments args;
165 Symbol* signature = NULL;
166
167 // ## TODO: type is only available in LocalVariable table, if present.
168 // ## StackValue type is T_INT or T_OBJECT.
169 switch (values->at(i)->type()) {
170 case T_INT:
171 args.push_int(values->int_at(i));
172 signature = vmSymbols::asPrimitive_int_signature();
173 break;
174
175 case T_LONG:
176 args.push_long(values->long_at(i));
177 signature = vmSymbols::asPrimitive_long_signature();
178 break;
179
180 case T_FLOAT:
181 args.push_float(values->float_at(i));
182 signature = vmSymbols::asPrimitive_float_signature();
183 break;
184
185 case T_DOUBLE:
186 args.push_double(values->double_at(i));
187 signature = vmSymbols::asPrimitive_double_signature();
188 break;
189
190 case T_BYTE:
191 args.push_int(values->int_at(i));
192 signature = vmSymbols::asPrimitive_byte_signature();
193 break;
194
195 case T_SHORT:
196 args.push_int(values->int_at(i));
197 signature = vmSymbols::asPrimitive_short_signature();
198 break;
199
200 case T_CHAR:
201 args.push_int(values->int_at(i));
202 signature = vmSymbols::asPrimitive_char_signature();
203 break;
204
205 case T_BOOLEAN:
206 args.push_int(values->int_at(i));
207 signature = vmSymbols::asPrimitive_boolean_signature();
208 break;
209
210 case T_OBJECT:
211 return values->obj_at(i)();
212
213 case T_CONFLICT:
214 // put a non-null slot
215 args.push_int(0);
216 signature = vmSymbols::asPrimitive_int_signature();
217 break;
218
219 default: ShouldNotReachHere();
220 }
221 JavaCalls::call_static(&result,
222 ik,
223 vmSymbols::asPrimitive_name(),
224 signature,
225 &args,
226 CHECK_NULL);
227 return (instanceOop) result.get_jobject();
228 }
229
230 static objArrayHandle values_to_object_array(StackValueCollection* values, TRAPS) {
231 objArrayHandle empty;
232 int length = values->size();
233 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
234 length, CHECK_(empty));
235 objArrayHandle array_h(THREAD, array_oop);
236 for (int i = 0; i < values->size(); i++) {
237 StackValue* st = values->at(i);
238 oop obj = create_primitive_value_instance(values, i, CHECK_(empty));
239 if (obj != NULL)
240 array_h->obj_at_put(i, obj);
241 }
242 return array_h;
243 }
244
245 static objArrayHandle monitors_to_object_array(GrowableArray<MonitorInfo*>* monitors, TRAPS) {
246 int length = monitors->length();
247 objArrayOop array_oop = oopFactory::new_objArray(SystemDictionary::Object_klass(),
248 length, CHECK_(objArrayHandle()));
249 objArrayHandle array_h(THREAD, array_oop);
250 for (int i = 0; i < length; i++) {
251 MonitorInfo* monitor = monitors->at(i);
252 array_h->obj_at_put(i, monitor->owner());
253 }
254 return array_h;
255 }
256
257 // Fill StackFrameInfo with declaringClass and bci and initialize memberName
258 void StackWalk::fill_stackframe(Handle stackFrame, const methodHandle& method, int bci) {
259 java_lang_StackFrameInfo::set_declaringClass(stackFrame(), method->method_holder()->java_mirror());
260 java_lang_StackFrameInfo::set_method_and_bci(stackFrame(), method, bci);
261 }
262
263 // Fill LiveStackFrameInfo with locals, monitors, and expressions
264 void StackWalk::fill_live_stackframe(Handle stackFrame, const methodHandle& method,
265 int bci, javaVFrame* jvf, TRAPS) {
266 fill_stackframe(stackFrame, method, bci);
267 if (jvf != NULL) {
268 StackValueCollection* locals = jvf->locals();
269 StackValueCollection* expressions = jvf->expressions();
270 GrowableArray<MonitorInfo*>* monitors = jvf->monitors();
271
272 if (!locals->is_empty()) {
273 objArrayHandle locals_h = values_to_object_array(locals, CHECK);
274 java_lang_LiveStackFrameInfo::set_locals(stackFrame(), locals_h());
275 }
276 if (!expressions->is_empty()) {
277 objArrayHandle expressions_h = values_to_object_array(expressions, CHECK);
278 java_lang_LiveStackFrameInfo::set_operands(stackFrame(), expressions_h());
279 }
280 if (monitors->length() > 0) {
281 objArrayHandle monitors_h = monitors_to_object_array(monitors, CHECK);
282 java_lang_LiveStackFrameInfo::set_monitors(stackFrame(), monitors_h());
283 }
284 }
285 }
286
287 // Begins stack walking.
288 //
289 // Parameters:
290 // stackStream StackStream object
291 // mode Stack walking mode.
292 // skip_frames Number of frames to be skipped.
293 // frame_count Number of frames to be traversed.
294 // start_index Start index to the user-supplied buffers.
295 // frames_array Buffer to store StackFrame in, starting at start_index.
296 // frames array is a Class<?>[] array when only getting caller
297 // reference, and a StackFrameInfo[] array (or derivative)
298 // otherwise. It should never be null.
299 //
300 // Returns Object returned from AbstractStackWalker::doStackWalk call.
301 //
302 oop StackWalk::walk(Handle stackStream, jlong mode,
303 int skip_frames, int frame_count, int start_index,
304 objArrayHandle frames_array,
305 TRAPS) {
306 ResourceMark rm(THREAD);
307 JavaThread* jt = (JavaThread*)THREAD;
308 if (TraceStackWalk) {
309 tty->print_cr("Start walking: mode " JLONG_FORMAT " skip %d frames batch size %d",
310 mode, skip_frames, frame_count);
311 }
312
313 if (frames_array.is_null()) {
314 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", NULL);
315 }
316
317 Klass* stackWalker_klass = SystemDictionary::StackWalker_klass();
318 Klass* abstractStackWalker_klass = SystemDictionary::AbstractStackWalker_klass();
319
320 methodHandle m_doStackWalk(THREAD, Universe::do_stack_walk_method());
321
322 // Setup traversal onto my stack.
323 RegisterMap regMap(jt, true);
324 JavaFrameStream stream(jt, ®Map);
325 {
326 while (!stream.at_end()) {
327 InstanceKlass* ik = stream.method()->method_holder();
328 if (ik != stackWalker_klass &&
329 ik != abstractStackWalker_klass && ik->super() != abstractStackWalker_klass) {
330 break;
331 }
332
333 if (TraceStackWalk) {
334 tty->print(" skip "); stream.method()->print_short_name(); tty->print("\n");
335 }
336 stream.next();
337 }
338
339 // stack frame has been traversed individually and resume stack walk
340 // from the stack frame at depth == skip_frames.
341 for (int n=0; n < skip_frames && !stream.at_end(); stream.next(), n++) {
342 if (TraceStackWalk) {
343 tty->print(" skip "); stream.method()->print_short_name();
344 tty->print_cr(" frame id: " PTR_FORMAT " pc: " PTR_FORMAT,
345 p2i(stream.java_frame()->fr().id()),
346 p2i(stream.java_frame()->fr().pc()));
347 }
348 }
349 }
350
351 int end_index = start_index;
352 int numFrames = 0;
353 if (!stream.at_end()) {
354 numFrames = fill_in_frames(mode, stream, frame_count, start_index,
355 frames_array, end_index, CHECK_NULL);
356 if (numFrames < 1) {
357 THROW_MSG_(vmSymbols::java_lang_InternalError(), "stack walk: decode failed", NULL);
358 }
359 }
360
361 // JVM_CallStackWalk walks the stack and fills in stack frames, then calls to
362 // Java method java.lang.StackStreamFactory.AbstractStackWalker::doStackWalk
363 // which calls the implementation to consume the stack frames.
364 // When JVM_CallStackWalk returns, it invalidates the stack stream.
365 JavaValue result(T_OBJECT);
366 JavaCallArguments args(stackStream);
367 args.push_long(stream.address_value());
368 args.push_int(skip_frames);
369 args.push_int(frame_count);
370 args.push_int(start_index);
371 args.push_int(end_index);
372
373 // Link the thread and vframe stream into the callee-visible object
374 stream.setup_magic_on_entry(frames_array);
375
376 JavaCalls::call(&result, m_doStackWalk, &args, THREAD);
377
378 // Do this before anything else happens, to disable any lingering stream objects
379 bool ok = stream.cleanup_magic_on_exit(frames_array);
380
381 // Throw pending exception if we must
382 (void) (CHECK_NULL);
383
384 if (!ok) {
385 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers on exit", NULL);
386 }
387
388 // Return normally
389 return (oop)result.get_jobject();
390 }
391
392 // Walk the next batch of stack frames
393 //
394 // Parameters:
395 // stackStream StackStream object
396 // mode Stack walking mode.
397 // magic Must be valid value to continue the stack walk
398 // frame_count Number of frames to be decoded.
399 // start_index Start index to the user-supplied buffers.
400 // frames_array Buffer to store StackFrame in, starting at start_index.
401 //
402 // Returns the end index of frame filled in the buffer.
403 //
404 jint StackWalk::moreFrames(Handle stackStream, jlong mode, jlong magic,
405 int frame_count, int start_index,
406 objArrayHandle frames_array,
407 TRAPS)
408 {
409 JavaThread* jt = (JavaThread*)THREAD;
410 JavaFrameStream* existing_stream = JavaFrameStream::from_current(jt, magic, frames_array);
411 if (existing_stream == NULL) {
412 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: corrupted buffers", 0L);
413 }
414
415 if (frames_array.is_null()) {
416 THROW_MSG_(vmSymbols::java_lang_NullPointerException(), "frames_array is NULL", 0L);
417 }
418
419 if (TraceStackWalk) {
420 tty->print_cr("StackWalk::moreFrames frame_count %d existing_stream " PTR_FORMAT " start %d frames %d",
421 frame_count, p2i(existing_stream), start_index, frames_array->length());
422 }
423 int end_index = start_index;
424 if (frame_count <= 0) {
425 return end_index; // No operation.
426 }
427
428 int count = frame_count + start_index;
429 assert (frames_array->length() >= count, "not enough space in buffers");
430
431 JavaFrameStream& stream = (*existing_stream);
432 if (!stream.at_end()) {
433 stream.next(); // advance past the last frame decoded in previous batch
434 if (!stream.at_end()) {
435 int n = fill_in_frames(mode, stream, frame_count, start_index,
436 frames_array, end_index, CHECK_0);
437 if (n < 1) {
438 THROW_MSG_(vmSymbols::java_lang_InternalError(), "doStackWalk: later decode failed", 0L);
439 }
440 return end_index;
441 }
442 }
443 return end_index;
444 }