1 /*
2 * Copyright (c) 2003, 2012, 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 "code/debugInfoRec.hpp"
27 #include "code/pcDesc.hpp"
28 #include "gc_interface/collectedHeap.inline.hpp"
29 #include "memory/space.hpp"
30 #include "memory/universe.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "oops/oop.inline2.hpp"
33 #include "prims/forte.hpp"
34 #include "runtime/thread.hpp"
35 #include "runtime/vframe.hpp"
36 #include "runtime/vframeArray.hpp"
37
38 // call frame copied from old .h file and renamed
39 typedef struct {
40 jint lineno; // line number in the source file
41 jmethodID method_id; // method executed in this frame
42 } ASGCT_CallFrame;
43
44 // call trace copied from old .h file and renamed
45 typedef struct {
46 JNIEnv *env_id; // Env where trace was recorded
47 jint num_frames; // number of frames in this trace
48 ASGCT_CallFrame *frames; // frames
49 } ASGCT_CallTrace;
50
51 // These name match the names reported by the forte quality kit
52 enum {
53 ticks_no_Java_frame = 0,
54 ticks_no_class_load = -1,
55 ticks_GC_active = -2,
56 ticks_unknown_not_Java = -3,
57 ticks_not_walkable_not_Java = -4,
58 ticks_unknown_Java = -5,
59 ticks_not_walkable_Java = -6,
60 ticks_unknown_state = -7,
61 ticks_thread_exit = -8,
62 ticks_deopt = -9,
63 ticks_safepoint = -10
64 };
65
66 #if INCLUDE_JVMTI
67
68 //-------------------------------------------------------
69
70 // Native interfaces for use by Forte tools.
71
72
73 #ifndef IA64
74
75 class vframeStreamForte : public vframeStreamCommon {
76 public:
77 // constructor that starts with sender of frame fr (top_frame)
78 vframeStreamForte(JavaThread *jt, frame fr, bool stop_at_java_call_stub);
79 void forte_next();
80 };
81
82
83 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, nmethod* nm);
84 static bool is_decipherable_interpreted_frame(JavaThread* thread,
85 frame* fr,
86 Method** method_p,
87 int* bci_p);
88
89
90
91
92 vframeStreamForte::vframeStreamForte(JavaThread *jt,
93 frame fr,
94 bool stop_at_java_call_stub) : vframeStreamCommon(jt) {
95
96 _stop_at_java_call_stub = stop_at_java_call_stub;
97 _frame = fr;
98
99 // We must always have a valid frame to start filling
100
101 bool filled_in = fill_from_frame();
102
103 assert(filled_in, "invariant");
104
105 }
106
107
108 // Solaris SPARC Compiler1 needs an additional check on the grandparent
109 // of the top_frame when the parent of the top_frame is interpreted and
110 // the grandparent is compiled. However, in this method we do not know
111 // the relationship of the current _frame relative to the top_frame so
112 // we implement a more broad sanity check. When the previous callee is
113 // interpreted and the current sender is compiled, we verify that the
114 // current sender is also walkable. If it is not walkable, then we mark
115 // the current vframeStream as at the end.
116 void vframeStreamForte::forte_next() {
117 // handle frames with inlining
118 if (_mode == compiled_mode &&
119 vframeStreamCommon::fill_in_compiled_inlined_sender()) {
120 return;
121 }
122
123 // handle general case
124
125 int loop_count = 0;
126 int loop_max = MaxJavaStackTraceDepth * 2;
127
128
129 do {
130
131 loop_count++;
132
133 // By the time we get here we should never see unsafe but better
134 // safe then segv'd
135
136 if (loop_count > loop_max || !_frame.safe_for_sender(_thread)) {
137 _mode = at_end_mode;
138 return;
139 }
140
141 _frame = _frame.sender(&_reg_map);
142
143 } while (!fill_from_frame());
144 }
145
146 // Determine if 'fr' is a decipherable compiled frame. We are already
147 // assured that fr is for a java nmethod.
148
149 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, nmethod* nm) {
150 assert(nm->is_java_method(), "invariant");
151
152 if (thread->has_last_Java_frame() && thread->last_Java_pc() == fr->pc()) {
153 // We're stopped at a call into the JVM so look for a PcDesc with
154 // the actual pc reported by the frame.
155 PcDesc* pc_desc = nm->pc_desc_at(fr->pc());
156
157 // Did we find a useful PcDesc?
158 if (pc_desc != NULL &&
159 pc_desc->scope_decode_offset() != DebugInformationRecorder::serialized_null) {
160 return true;
161 }
162 }
163
164 // We're at some random pc in the nmethod so search for the PcDesc
165 // whose pc is greater than the current PC. It's done this way
166 // because the extra PcDescs that are recorded for improved debug
167 // info record the end of the region covered by the ScopeDesc
168 // instead of the beginning.
169 PcDesc* pc_desc = nm->pc_desc_near(fr->pc() + 1);
170
171 // Now do we have a useful PcDesc?
172 if (pc_desc == NULL ||
173 pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) {
174 // No debug information available for this pc
175 // vframeStream would explode if we try and walk the frames.
176 return false;
177 }
178
179 // This PcDesc is useful however we must adjust the frame's pc
180 // so that the vframeStream lookups will use this same pc
181 fr->set_pc(pc_desc->real_pc(nm));
182 return true;
183 }
184
185
186 // Determine if 'fr' is a walkable interpreted frame. Returns false
187 // if it is not. *method_p, and *bci_p are not set when false is
188 // returned. *method_p is non-NULL if frame was executing a Java
189 // method. *bci_p is != -1 if a valid BCI in the Java method could
190 // be found.
191 // Note: this method returns true when a valid Java method is found
192 // even if a valid BCI cannot be found.
193
194 static bool is_decipherable_interpreted_frame(JavaThread* thread,
195 frame* fr,
196 Method** method_p,
197 int* bci_p) {
198 assert(fr->is_interpreted_frame(), "just checking");
199
200 // top frame is an interpreted frame
201 // check if it is walkable (i.e. valid Method* and valid bci)
202
203 // Because we may be racing a gc thread the method and/or bci
204 // of a valid interpreter frame may look bad causing us to
205 // fail the is_interpreted_frame_valid test. If the thread
206 // is in any of the following states we are assured that the
207 // frame is in fact valid and we must have hit the race.
208
209 JavaThreadState state = thread->thread_state();
210 bool known_valid = (state == _thread_in_native ||
211 state == _thread_in_vm ||
212 state == _thread_blocked );
213
214 if (known_valid || fr->is_interpreted_frame_valid(thread)) {
215
216 // The frame code should completely validate the frame so that
217 // references to Method* and bci are completely safe to access
218 // If they aren't the frame code should be fixed not this
219 // code. However since gc isn't locked out the values could be
220 // stale. This is a race we can never completely win since we can't
221 // lock out gc so do one last check after retrieving their values
222 // from the frame for additional safety
223
224 Method* method = fr->interpreter_frame_method();
225
226 // We've at least found a method.
227 // NOTE: there is something to be said for the approach that
228 // if we don't find a valid bci then the method is not likely
229 // a valid method. Then again we may have caught an interpreter
230 // frame in the middle of construction and the bci field is
231 // not yet valid.
232
233 *method_p = method;
234 if (!method->is_valid_method()) return false;
235
236 intptr_t bcx = fr->interpreter_frame_bcx();
237
238 int bci = method->validate_bci_from_bcx(bcx);
239
240 // note: bci is set to -1 if not a valid bci
241 *bci_p = bci;
242 return true;
243 }
244
245 return false;
246 }
247
248
249 // Determine if 'fr' can be used to find an initial Java frame.
250 // Return false if it can not find a fully decipherable Java frame
251 // (in other words a frame that isn't safe to use in a vframe stream).
252 // Obviously if it can't even find a Java frame false will also be returned.
253 //
254 // If we find a Java frame decipherable or not then by definition we have
255 // identified a method and that will be returned to the caller via method_p.
256 // If we can determine a bci that is returned also. (Hmm is it possible
257 // to return a method and bci and still return false? )
258 //
259 // The initial Java frame we find (if any) is return via initial_frame_p.
260 //
261
262 static bool find_initial_Java_frame(JavaThread* thread,
263 frame* fr,
264 frame* initial_frame_p,
265 Method** method_p,
266 int* bci_p) {
267
268 // It is possible that for a frame containing an nmethod
269 // we can capture the method but no bci. If we get no
270 // bci the frame isn't walkable but the method is usable.
271 // Therefore we init the returned Method* to NULL so the
272 // caller can make the distinction.
273
274 *method_p = NULL;
275
276 // On the initial call to this method the frame we get may not be
277 // recognizable to us. This should only happen if we are in a JRT_LEAF
278 // or something called by a JRT_LEAF method.
279
280
281
282 frame candidate = *fr;
283
284 // If the starting frame we were given has no codeBlob associated with
285 // it see if we can find such a frame because only frames with codeBlobs
286 // are possible Java frames.
287
288 if (fr->cb() == NULL) {
289
290 // See if we can find a useful frame
291 int loop_count;
292 int loop_max = MaxJavaStackTraceDepth * 2;
293 RegisterMap map(thread, false);
294
295 for (loop_count = 0; loop_count < loop_max; loop_count++) {
296 if (!candidate.safe_for_sender(thread)) return false;
297 candidate = candidate.sender(&map);
298 if (candidate.cb() != NULL) break;
299 }
300 if (candidate.cb() == NULL) return false;
301 }
302
303 // We have a frame known to be in the codeCache
304 // We will hopefully be able to figure out something to do with it.
305 int loop_count;
306 int loop_max = MaxJavaStackTraceDepth * 2;
307 RegisterMap map(thread, false);
308
309 for (loop_count = 0; loop_count < loop_max; loop_count++) {
310
311 if (candidate.is_first_frame()) {
312 // If initial frame is frame from StubGenerator and there is no
313 // previous anchor, there are no java frames associated with a method
314 return false;
315 }
316
317 if (candidate.is_interpreted_frame()) {
318 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
319 *initial_frame_p = candidate;
320 return true;
321 }
322
323 // Hopefully we got some data
324 return false;
325 }
326
327 if (candidate.cb()->is_nmethod()) {
328
329 nmethod* nm = (nmethod*) candidate.cb();
330 *method_p = nm->method();
331
332 // If the frame isn't fully decipherable then the default
333 // value for the bci is a signal that we don't have a bci.
334 // If we have a decipherable frame this bci value will
335 // not be used.
336
337 *bci_p = -1;
338
339 *initial_frame_p = candidate;
340
341 // Native wrapper code is trivial to decode by vframeStream
342
343 if (nm->is_native_method()) return true;
344
345 // If it isn't decipherable then we have found a pc that doesn't
346 // have a PCDesc that can get us a bci however we did find
347 // a method
348
349 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) {
350 return false;
351 }
352
353 // is_decipherable_compiled_frame may modify candidate's pc
354 *initial_frame_p = candidate;
355
356 assert(nm->pc_desc_at(candidate.pc()) != NULL, "if it's decipherable then pc must be valid");
357
358 return true;
359 }
360
361 // Must be some stub frame that we don't care about
362
363 if (!candidate.safe_for_sender(thread)) return false;
364 candidate = candidate.sender(&map);
365
366 // If it isn't in the code cache something is wrong
367 // since once we find a frame in the code cache they
368 // all should be there.
369
370 if (candidate.cb() == NULL) return false;
371
372 }
373
374 return false;
375
376 }
377
378 static void forte_fill_call_trace_given_top(JavaThread* thd,
379 ASGCT_CallTrace* trace,
380 int depth,
381 frame top_frame) {
382 NoHandleMark nhm;
383
384 frame initial_Java_frame;
385 Method* method;
386 int bci;
387 int count;
388
389 count = 0;
390 assert(trace->frames != NULL, "trace->frames must be non-NULL");
391
392 bool fully_decipherable = find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
393
394 // The frame might not be walkable but still recovered a method
395 // (e.g. an nmethod with no scope info for the pc)
396
397 if (method == NULL) return;
398
399 if (!method->is_valid_method()) {
400 trace->num_frames = ticks_GC_active; // -2
401 return;
402 }
403
404 // We got a Java frame however it isn't fully decipherable
405 // so it won't necessarily be safe to use it for the
406 // initial frame in the vframe stream.
407
408 if (!fully_decipherable) {
409 // Take whatever method the top-frame decoder managed to scrape up.
410 // We look further at the top frame only if non-safepoint
411 // debugging information is available.
412 count++;
413 trace->num_frames = count;
414 trace->frames[0].method_id = method->find_jmethod_id_or_null();
415 if (!method->is_native()) {
416 trace->frames[0].lineno = bci;
417 } else {
418 trace->frames[0].lineno = -3;
419 }
420
421 if (!initial_Java_frame.safe_for_sender(thd)) return;
422
423 RegisterMap map(thd, false);
424 initial_Java_frame = initial_Java_frame.sender(&map);
425 }
426
427 vframeStreamForte st(thd, initial_Java_frame, false);
428
429 for (; !st.at_end() && count < depth; st.forte_next(), count++) {
430 bci = st.bci();
431 method = st.method();
432
433 if (!method->is_valid_method()) {
434 // we throw away everything we've gathered in this sample since
435 // none of it is safe
436 trace->num_frames = ticks_GC_active; // -2
437 return;
438 }
439
440 trace->frames[count].method_id = method->find_jmethod_id_or_null();
441 if (!method->is_native()) {
442 trace->frames[count].lineno = bci;
443 } else {
444 trace->frames[count].lineno = -3;
445 }
446 }
447 trace->num_frames = count;
448 return;
449 }
450
451
452 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
453 // on Linux X86, Solaris SPARC and Solaris X86.
454 //
455 // Async-safe version of GetCallTrace being called from a signal handler
456 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
457 // with different content (see below).
458 //
459 // This function must only be called when JVM/TI
460 // CLASS_LOAD events have been enabled since agent startup. The enabled
461 // event will cause the jmethodIDs to be allocated at class load time.
462 // The jmethodIDs cannot be allocated in a signal handler because locks
463 // cannot be grabbed in a signal handler safely.
464 //
465 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
466 //
467 // Called by the profiler to obtain the current method call stack trace for
468 // a given thread. The thread is identified by the env_id field in the
469 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
470 // structure with enough memory for the requested stack depth. The VM fills in
471 // the frames buffer and the num_frames field.
472 //
473 // Arguments:
474 //
475 // trace - trace data structure to be filled by the VM.
476 // depth - depth of the call stack trace.
477 // ucontext - ucontext_t of the LWP
478 //
479 // ASGCT_CallTrace:
480 // typedef struct {
481 // JNIEnv *env_id;
482 // jint num_frames;
483 // ASGCT_CallFrame *frames;
484 // } ASGCT_CallTrace;
485 //
486 // Fields:
487 // env_id - ID of thread which executed this trace.
488 // num_frames - number of frames in the trace.
489 // (< 0 indicates the frame is not walkable).
490 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
491 //
492 // ASGCT_CallFrame:
493 // typedef struct {
494 // jint lineno;
495 // jmethodID method_id;
496 // } ASGCT_CallFrame;
497 //
498 // Fields:
499 // 1) For Java frame (interpreted and compiled),
500 // lineno - bci of the method being executed or -1 if bci is not available
501 // method_id - jmethodID of the method being executed
502 // 2) For native method
503 // lineno - (-3)
504 // method_id - jmethodID of the method being executed
505
506 extern "C" {
507 JNIEXPORT
508 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
509 JavaThread* thread;
510
511 if (trace->env_id == NULL ||
512 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
513 thread->is_exiting()) {
514
515 // bad env_id, thread has exited or thread is exiting
516 trace->num_frames = ticks_thread_exit; // -8
517 return;
518 }
519
520 if (thread->in_deopt_handler()) {
521 // thread is in the deoptimization handler so return no frames
522 trace->num_frames = ticks_deopt; // -9
523 return;
524 }
525
526 assert(JavaThread::current() == thread,
527 "AsyncGetCallTrace must be called by the current interrupted thread");
528
529 if (!JvmtiExport::should_post_class_load()) {
530 trace->num_frames = ticks_no_class_load; // -1
531 return;
532 }
533
534 if (Universe::heap()->is_gc_active()) {
535 trace->num_frames = ticks_GC_active; // -2
536 return;
537 }
538
539 switch (thread->thread_state()) {
540 case _thread_new:
541 case _thread_uninitialized:
542 case _thread_new_trans:
543 // We found the thread on the threads list above, but it is too
544 // young to be useful so return that there are no Java frames.
545 trace->num_frames = 0;
546 break;
547 case _thread_in_native:
548 case _thread_in_native_trans:
549 case _thread_blocked:
550 case _thread_blocked_trans:
551 case _thread_in_vm:
552 case _thread_in_vm_trans:
553 {
554 frame fr;
555
556 // param isInJava == false - indicate we aren't in Java code
557 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
558 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
559 } else {
560 if (!thread->has_last_Java_frame()) {
561 trace->num_frames = 0; // No Java frames
562 } else {
563 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
564 forte_fill_call_trace_given_top(thread, trace, depth, fr);
565
566 // This assert would seem to be valid but it is not.
567 // It would be valid if we weren't possibly racing a gc
568 // thread. A gc thread can make a valid interpreted frame
569 // look invalid. It's a small window but it does happen.
570 // The assert is left here commented out as a reminder.
571 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
572
573 }
574 }
575 }
576 break;
577 case _thread_in_Java:
578 case _thread_in_Java_trans:
579 {
580 frame fr;
581
582 // param isInJava == true - indicate we are in Java code
583 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
584 trace->num_frames = ticks_unknown_Java; // -5 unknown frame
585 } else {
586 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
587 forte_fill_call_trace_given_top(thread, trace, depth, fr);
588 }
589 }
590 break;
591 default:
592 // Unknown thread state
593 trace->num_frames = ticks_unknown_state; // -7
594 break;
595 }
596 }
597
598
599 #ifndef _WINDOWS
600 // Support for the Forte(TM) Peformance Tools collector.
601 //
602 // The method prototype is derived from libcollector.h. For more
603 // information, please see the libcollect man page.
604
605 // Method to let libcollector know about a dynamically loaded function.
606 // Because it is weakly bound, the calls become NOP's when the library
607 // isn't present.
608 #ifdef __APPLE__
609 // XXXDARWIN: Link errors occur even when __attribute__((weak_import))
610 // is added
611 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) (0)
612 #else
613 void collector_func_load(char* name,
614 void* null_argument_1,
615 void* null_argument_2,
616 void *vaddr,
617 int size,
618 int zero_argument,
619 void* null_argument_3);
620 #pragma weak collector_func_load
621 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
622 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 )
623 #endif // __APPLE__
624 #endif // !_WINDOWS
625
626 } // end extern "C"
627 #endif // !IA64
628
629 void Forte::register_stub(const char* name, address start, address end) {
630 #if !defined(_WINDOWS) && !defined(IA64)
631 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
632 "Code size exceeds maximum range");
633
634 collector_func_load((char*)name, NULL, NULL, start,
635 pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
636 #endif // !_WINDOWS && !IA64
637 }
638
639 #else // INCLUDE_JVMTI
640 extern "C" {
641 JNIEXPORT
642 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
643 trace->num_frames = ticks_no_class_load; // -1
644 }
645 }
646 #endif // INCLUDE_JVMTI