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/javaCalls.hpp"
35 #include "runtime/thread.hpp"
36 #include "runtime/vframe.hpp"
37 #include "runtime/vframeArray.hpp"
38
39 // call frame copied from old .h file and renamed
40 typedef struct {
41 jint lineno; // line number in the source file
42 jmethodID method_id; // method executed in this frame
43 } ASGCT_CallFrame;
44
45 // call trace copied from old .h file and renamed
46 typedef struct {
47 JNIEnv *env_id; // Env where trace was recorded
48 jint num_frames; // number of frames in this trace
49 ASGCT_CallFrame *frames; // frames
50 } ASGCT_CallTrace;
51
52 // These name match the names reported by the forte quality kit
53 enum {
54 ticks_no_Java_frame = 0,
55 ticks_no_class_load = -1,
56 ticks_GC_active = -2,
57 ticks_unknown_not_Java = -3,
58 ticks_not_walkable_not_Java = -4,
59 ticks_unknown_Java = -5,
60 ticks_not_walkable_Java = -6,
61 ticks_unknown_state = -7,
62 ticks_thread_exit = -8,
63 ticks_deopt = -9,
64 ticks_safepoint = -10
65 };
66
67 #if INCLUDE_JVMTI
68
69 //-------------------------------------------------------
70
71 // Native interfaces for use by Forte tools.
72
73
74 #ifndef IA64
75
76 class vframeStreamForte : public vframeStreamCommon {
77 public:
78 // constructor that starts with sender of frame fr (top_frame)
79 vframeStreamForte(JavaThread *jt, frame fr, bool stop_at_java_call_stub);
80 void forte_next();
81 };
82
83
84 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, nmethod* nm);
85 static bool is_decipherable_interpreted_frame(JavaThread* thread,
86 frame* fr,
87 Method** method_p,
88 int* bci_p);
89
90
91
92
93 vframeStreamForte::vframeStreamForte(JavaThread *jt,
94 frame fr,
95 bool stop_at_java_call_stub) : vframeStreamCommon(jt) {
96
97 _stop_at_java_call_stub = stop_at_java_call_stub;
98 _frame = fr;
99
100 // We must always have a valid frame to start filling
101
102 bool filled_in = fill_from_frame();
103
104 assert(filled_in, "invariant");
105
106 }
107
108
109 // Solaris SPARC Compiler1 needs an additional check on the grandparent
110 // of the top_frame when the parent of the top_frame is interpreted and
111 // the grandparent is compiled. However, in this method we do not know
112 // the relationship of the current _frame relative to the top_frame so
113 // we implement a more broad sanity check. When the previous callee is
114 // interpreted and the current sender is compiled, we verify that the
115 // current sender is also walkable. If it is not walkable, then we mark
116 // the current vframeStream as at the end.
117 void vframeStreamForte::forte_next() {
118 // handle frames with inlining
119 if (_mode == compiled_mode &&
120 vframeStreamCommon::fill_in_compiled_inlined_sender()) {
121 return;
122 }
123
124 // handle general case
125
126 int loop_count = 0;
127 int loop_max = MaxJavaStackTraceDepth * 2;
128
129
130 do {
131
132 loop_count++;
133
134 // By the time we get here we should never see unsafe but better
135 // safe then segv'd
136
137 if (loop_count > loop_max || !_frame.safe_for_sender(_thread)) {
138 _mode = at_end_mode;
139 return;
140 }
141
142 _frame = _frame.sender(&_reg_map);
143
144 } while (!fill_from_frame());
145 }
146
147 // Determine if 'fr' is a decipherable compiled frame. We are already
148 // assured that fr is for a java nmethod.
149
150 static bool is_decipherable_compiled_frame(JavaThread* thread, frame* fr, nmethod* nm) {
151 assert(nm->is_java_method(), "invariant");
152
153 if (thread->has_last_Java_frame() && thread->last_Java_pc() == fr->pc()) {
154 // We're stopped at a call into the JVM so look for a PcDesc with
155 // the actual pc reported by the frame.
156 PcDesc* pc_desc = nm->pc_desc_at(fr->pc());
157
158 // Did we find a useful PcDesc?
159 if (pc_desc != NULL &&
160 pc_desc->scope_decode_offset() != DebugInformationRecorder::serialized_null) {
161 return true;
162 }
163 }
164
165 // We're at some random pc in the nmethod so search for the PcDesc
166 // whose pc is greater than the current PC. It's done this way
167 // because the extra PcDescs that are recorded for improved debug
168 // info record the end of the region covered by the ScopeDesc
169 // instead of the beginning.
170 PcDesc* pc_desc = nm->pc_desc_near(fr->pc() + 1);
171
172 // Now do we have a useful PcDesc?
173 if (pc_desc == NULL ||
174 pc_desc->scope_decode_offset() == DebugInformationRecorder::serialized_null) {
175 // No debug information available for this pc
176 // vframeStream would explode if we try and walk the frames.
177 return false;
178 }
179
180 // This PcDesc is useful however we must adjust the frame's pc
181 // so that the vframeStream lookups will use this same pc
182 fr->set_pc(pc_desc->real_pc(nm));
183 return true;
184 }
185
186
187 // Determine if 'fr' is a walkable interpreted frame. Returns false
188 // if it is not. *method_p, and *bci_p are not set when false is
189 // returned. *method_p is non-NULL if frame was executing a Java
190 // method. *bci_p is != -1 if a valid BCI in the Java method could
191 // be found.
192 // Note: this method returns true when a valid Java method is found
193 // even if a valid BCI cannot be found.
194
195 static bool is_decipherable_interpreted_frame(JavaThread* thread,
196 frame* fr,
197 Method** method_p,
198 int* bci_p) {
199 assert(fr->is_interpreted_frame(), "just checking");
200
201 // top frame is an interpreted frame
202 // check if it is walkable (i.e. valid Method* and valid bci)
203
204 // Because we may be racing a gc thread the method and/or bci
205 // of a valid interpreter frame may look bad causing us to
206 // fail the is_interpreted_frame_valid test. If the thread
207 // is in any of the following states we are assured that the
208 // frame is in fact valid and we must have hit the race.
209
210 JavaThreadState state = thread->thread_state();
211 bool known_valid = (state == _thread_in_native ||
212 state == _thread_in_vm ||
213 state == _thread_blocked );
214
215 if (known_valid || fr->is_interpreted_frame_valid(thread)) {
216
217 // The frame code should completely validate the frame so that
218 // references to Method* and bci are completely safe to access
219 // If they aren't the frame code should be fixed not this
220 // code. However since gc isn't locked out the values could be
221 // stale. This is a race we can never completely win since we can't
222 // lock out gc so do one last check after retrieving their values
223 // from the frame for additional safety
224
225 Method* method = fr->interpreter_frame_method();
226
227 // We've at least found a method.
228 // NOTE: there is something to be said for the approach that
229 // if we don't find a valid bci then the method is not likely
230 // a valid method. Then again we may have caught an interpreter
231 // frame in the middle of construction and the bci field is
232 // not yet valid.
233
234 *method_p = method;
235 if (!method->is_valid_method()) return false;
236
237 intptr_t bcx = fr->interpreter_frame_bcx();
238
239 int bci = method->validate_bci_from_bcx(bcx);
240
241 // note: bci is set to -1 if not a valid bci
242 *bci_p = bci;
243 return true;
244 }
245
246 return false;
247 }
248
249
250 // Determine if 'fr' can be used to find an initial Java frame.
251 // Return false if it can not find a fully decipherable Java frame
252 // (in other words a frame that isn't safe to use in a vframe stream).
253 // Obviously if it can't even find a Java frame false will also be returned.
254 //
255 // If we find a Java frame decipherable or not then by definition we have
256 // identified a method and that will be returned to the caller via method_p.
257 // If we can determine a bci that is returned also. (Hmm is it possible
258 // to return a method and bci and still return false? )
259 //
260 // The initial Java frame we find (if any) is return via initial_frame_p.
261 //
262
263 static bool find_initial_Java_frame(JavaThread* thread,
264 frame* fr,
265 frame* initial_frame_p,
266 Method** method_p,
267 int* bci_p) {
268
269 // It is possible that for a frame containing an nmethod
270 // we can capture the method but no bci. If we get no
271 // bci the frame isn't walkable but the method is usable.
272 // Therefore we init the returned Method* to NULL so the
273 // caller can make the distinction.
274
275 *method_p = NULL;
276
277 // On the initial call to this method the frame we get may not be
278 // recognizable to us. This should only happen if we are in a JRT_LEAF
279 // or something called by a JRT_LEAF method.
280
281
282
283 frame candidate = *fr;
284
285 // If the starting frame we were given has no codeBlob associated with
286 // it see if we can find such a frame because only frames with codeBlobs
287 // are possible Java frames.
288
289 if (fr->cb() == NULL) {
290
291 // See if we can find a useful frame
292 int loop_count;
293 int loop_max = MaxJavaStackTraceDepth * 2;
294 RegisterMap map(thread, false);
295
296 for (loop_count = 0; loop_count < loop_max; loop_count++) {
297 if (!candidate.safe_for_sender(thread)) return false;
298 candidate = candidate.sender(&map);
299 if (candidate.cb() != NULL) break;
300 }
301 if (candidate.cb() == NULL) return false;
302 }
303
304 // We have a frame known to be in the codeCache
305 // We will hopefully be able to figure out something to do with it.
306 int loop_count;
307 int loop_max = MaxJavaStackTraceDepth * 2;
308 RegisterMap map(thread, false);
309
310 for (loop_count = 0; loop_count < loop_max; loop_count++) {
311
312 if (candidate.is_entry_frame()) {
313 // jcw is NULL if the java call wrapper couldn't be found
314 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread);
315 // If initial frame is frame from StubGenerator and there is no
316 // previous anchor, there are no java frames associated with a method
317 if (jcw == NULL || jcw->is_first_frame()) {
318 return false;
319 }
320 }
321
322 if (candidate.is_interpreted_frame()) {
323 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
324 *initial_frame_p = candidate;
325 return true;
326 }
327
328 // Hopefully we got some data
329 return false;
330 }
331
332 if (candidate.cb()->is_nmethod()) {
333
334 nmethod* nm = (nmethod*) candidate.cb();
335 *method_p = nm->method();
336
337 // If the frame isn't fully decipherable then the default
338 // value for the bci is a signal that we don't have a bci.
339 // If we have a decipherable frame this bci value will
340 // not be used.
341
342 *bci_p = -1;
343
344 *initial_frame_p = candidate;
345
346 // Native wrapper code is trivial to decode by vframeStream
347
348 if (nm->is_native_method()) return true;
349
350 // If it isn't decipherable then we have found a pc that doesn't
351 // have a PCDesc that can get us a bci however we did find
352 // a method
353
354 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) {
355 return false;
356 }
357
358 // is_decipherable_compiled_frame may modify candidate's pc
359 *initial_frame_p = candidate;
360
361 assert(nm->pc_desc_at(candidate.pc()) != NULL, "if it's decipherable then pc must be valid");
362
363 return true;
364 }
365
366 // Must be some stub frame that we don't care about
367
368 if (!candidate.safe_for_sender(thread)) return false;
369 candidate = candidate.sender(&map);
370
371 // If it isn't in the code cache something is wrong
372 // since once we find a frame in the code cache they
373 // all should be there.
374
375 if (candidate.cb() == NULL) return false;
376
377 }
378
379 return false;
380
381 }
382
383 static void forte_fill_call_trace_given_top(JavaThread* thd,
384 ASGCT_CallTrace* trace,
385 int depth,
386 frame top_frame) {
387 NoHandleMark nhm;
388
389 frame initial_Java_frame;
390 Method* method;
391 int bci;
392 int count;
393
394 count = 0;
395 assert(trace->frames != NULL, "trace->frames must be non-NULL");
396
397 bool fully_decipherable = find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
398
399 // The frame might not be walkable but still recovered a method
400 // (e.g. an nmethod with no scope info for the pc)
401
402 if (method == NULL) return;
403
404 if (!method->is_valid_method()) {
405 trace->num_frames = ticks_GC_active; // -2
406 return;
407 }
408
409 // We got a Java frame however it isn't fully decipherable
410 // so it won't necessarily be safe to use it for the
411 // initial frame in the vframe stream.
412
413 if (!fully_decipherable) {
414 // Take whatever method the top-frame decoder managed to scrape up.
415 // We look further at the top frame only if non-safepoint
416 // debugging information is available.
417 count++;
418 trace->num_frames = count;
419 trace->frames[0].method_id = method->find_jmethod_id_or_null();
420 if (!method->is_native()) {
421 trace->frames[0].lineno = bci;
422 } else {
423 trace->frames[0].lineno = -3;
424 }
425
426 if (!initial_Java_frame.safe_for_sender(thd)) return;
427
428 RegisterMap map(thd, false);
429 initial_Java_frame = initial_Java_frame.sender(&map);
430 }
431
432 vframeStreamForte st(thd, initial_Java_frame, false);
433
434 for (; !st.at_end() && count < depth; st.forte_next(), count++) {
435 bci = st.bci();
436 method = st.method();
437
438 if (!method->is_valid_method()) {
439 // we throw away everything we've gathered in this sample since
440 // none of it is safe
441 trace->num_frames = ticks_GC_active; // -2
442 return;
443 }
444
445 trace->frames[count].method_id = method->find_jmethod_id_or_null();
446 if (!method->is_native()) {
447 trace->frames[count].lineno = bci;
448 } else {
449 trace->frames[count].lineno = -3;
450 }
451 }
452 trace->num_frames = count;
453 return;
454 }
455
456
457 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
458 // on Linux X86, Solaris SPARC and Solaris X86.
459 //
460 // Async-safe version of GetCallTrace being called from a signal handler
461 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
462 // with different content (see below).
463 //
464 // This function must only be called when JVM/TI
465 // CLASS_LOAD events have been enabled since agent startup. The enabled
466 // event will cause the jmethodIDs to be allocated at class load time.
467 // The jmethodIDs cannot be allocated in a signal handler because locks
468 // cannot be grabbed in a signal handler safely.
469 //
470 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
471 //
472 // Called by the profiler to obtain the current method call stack trace for
473 // a given thread. The thread is identified by the env_id field in the
474 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
475 // structure with enough memory for the requested stack depth. The VM fills in
476 // the frames buffer and the num_frames field.
477 //
478 // Arguments:
479 //
480 // trace - trace data structure to be filled by the VM.
481 // depth - depth of the call stack trace.
482 // ucontext - ucontext_t of the LWP
483 //
484 // ASGCT_CallTrace:
485 // typedef struct {
486 // JNIEnv *env_id;
487 // jint num_frames;
488 // ASGCT_CallFrame *frames;
489 // } ASGCT_CallTrace;
490 //
491 // Fields:
492 // env_id - ID of thread which executed this trace.
493 // num_frames - number of frames in the trace.
494 // (< 0 indicates the frame is not walkable).
495 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
496 //
497 // ASGCT_CallFrame:
498 // typedef struct {
499 // jint lineno;
500 // jmethodID method_id;
501 // } ASGCT_CallFrame;
502 //
503 // Fields:
504 // 1) For Java frame (interpreted and compiled),
505 // lineno - bci of the method being executed or -1 if bci is not available
506 // method_id - jmethodID of the method being executed
507 // 2) For native method
508 // lineno - (-3)
509 // method_id - jmethodID of the method being executed
510
511 extern "C" {
512 JNIEXPORT
513 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
514 JavaThread* thread;
515
516 if (trace->env_id == NULL ||
517 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
518 thread->is_exiting()) {
519
520 // bad env_id, thread has exited or thread is exiting
521 trace->num_frames = ticks_thread_exit; // -8
522 return;
523 }
524
525 if (thread->in_deopt_handler()) {
526 // thread is in the deoptimization handler so return no frames
527 trace->num_frames = ticks_deopt; // -9
528 return;
529 }
530
531 assert(JavaThread::current() == thread,
532 "AsyncGetCallTrace must be called by the current interrupted thread");
533
534 if (!JvmtiExport::should_post_class_load()) {
535 trace->num_frames = ticks_no_class_load; // -1
536 return;
537 }
538
539 if (Universe::heap()->is_gc_active()) {
540 trace->num_frames = ticks_GC_active; // -2
541 return;
542 }
543
544 switch (thread->thread_state()) {
545 case _thread_new:
546 case _thread_uninitialized:
547 case _thread_new_trans:
548 // We found the thread on the threads list above, but it is too
549 // young to be useful so return that there are no Java frames.
550 trace->num_frames = 0;
551 break;
552 case _thread_in_native:
553 case _thread_in_native_trans:
554 case _thread_blocked:
555 case _thread_blocked_trans:
556 case _thread_in_vm:
557 case _thread_in_vm_trans:
558 {
559 frame fr;
560
561 // param isInJava == false - indicate we aren't in Java code
562 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
563 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
564 } else {
565 if (!thread->has_last_Java_frame()) {
566 trace->num_frames = 0; // No Java frames
567 } else {
568 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
569 forte_fill_call_trace_given_top(thread, trace, depth, fr);
570
571 // This assert would seem to be valid but it is not.
572 // It would be valid if we weren't possibly racing a gc
573 // thread. A gc thread can make a valid interpreted frame
574 // look invalid. It's a small window but it does happen.
575 // The assert is left here commented out as a reminder.
576 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
577
578 }
579 }
580 }
581 break;
582 case _thread_in_Java:
583 case _thread_in_Java_trans:
584 {
585 frame fr;
586
587 // param isInJava == true - indicate we are in Java code
588 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
589 trace->num_frames = ticks_unknown_Java; // -5 unknown frame
590 } else {
591 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
592 forte_fill_call_trace_given_top(thread, trace, depth, fr);
593 }
594 }
595 break;
596 default:
597 // Unknown thread state
598 trace->num_frames = ticks_unknown_state; // -7
599 break;
600 }
601 }
602
603
604 #ifndef _WINDOWS
605 // Support for the Forte(TM) Peformance Tools collector.
606 //
607 // The method prototype is derived from libcollector.h. For more
608 // information, please see the libcollect man page.
609
610 // Method to let libcollector know about a dynamically loaded function.
611 // Because it is weakly bound, the calls become NOP's when the library
612 // isn't present.
613 #ifdef __APPLE__
614 // XXXDARWIN: Link errors occur even when __attribute__((weak_import))
615 // is added
616 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) (0)
617 #else
618 void collector_func_load(char* name,
619 void* null_argument_1,
620 void* null_argument_2,
621 void *vaddr,
622 int size,
623 int zero_argument,
624 void* null_argument_3);
625 #pragma weak collector_func_load
626 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
627 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 )
628 #endif // __APPLE__
629 #endif // !_WINDOWS
630
631 } // end extern "C"
632 #endif // !IA64
633
634 void Forte::register_stub(const char* name, address start, address end) {
635 #if !defined(_WINDOWS) && !defined(IA64)
636 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
637 "Code size exceeds maximum range");
638
639 collector_func_load((char*)name, NULL, NULL, start,
640 pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
641 #endif // !_WINDOWS && !IA64
642 }
643
644 #else // INCLUDE_JVMTI
645 extern "C" {
646 JNIEXPORT
647 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
648 trace->num_frames = ticks_no_class_load; // -1
649 }
650 }
651 #endif // INCLUDE_JVMTI