1 /*
2 * Copyright (c) 2003, 2014, 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.inline.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 #if !defined(IA64) && !defined(PPC64)
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 address bcp = fr->interpreter_frame_bcp();
238 int bci = method->validate_bci_from_bcp(bcp);
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_entry_frame()) {
312 // jcw is NULL if the java call wrapper couldn't be found
313 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread);
314 // If initial frame is frame from StubGenerator and there is no
315 // previous anchor, there are no java frames associated with a method
316 if (jcw == NULL || jcw->is_first_frame()) {
317 return false;
318 }
319 }
320
321 if (candidate.is_interpreted_frame()) {
322 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
323 *initial_frame_p = candidate;
324 return true;
325 }
326
327 // Hopefully we got some data
328 return false;
329 }
330
331 if (candidate.cb()->is_nmethod()) {
332
333 nmethod* nm = (nmethod*) candidate.cb();
334 *method_p = nm->method();
335
336 // If the frame isn't fully decipherable then the default
337 // value for the bci is a signal that we don't have a bci.
338 // If we have a decipherable frame this bci value will
339 // not be used.
340
341 *bci_p = -1;
342
343 *initial_frame_p = candidate;
344
345 // Native wrapper code is trivial to decode by vframeStream
346
347 if (nm->is_native_method()) return true;
348
349 // If it isn't decipherable then we have found a pc that doesn't
350 // have a PCDesc that can get us a bci however we did find
351 // a method
352
353 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) {
354 return false;
355 }
356
357 // is_decipherable_compiled_frame may modify candidate's pc
358 *initial_frame_p = candidate;
359
360 assert(nm->pc_desc_at(candidate.pc()) != NULL, "if it's decipherable then pc must be valid");
361
362 return true;
363 }
364
365 // Must be some stub frame that we don't care about
366
367 if (!candidate.safe_for_sender(thread)) return false;
368 candidate = candidate.sender(&map);
369
370 // If it isn't in the code cache something is wrong
371 // since once we find a frame in the code cache they
372 // all should be there.
373
374 if (candidate.cb() == NULL) return false;
375
376 }
377
378 return false;
379
380 }
381
382 static void forte_fill_call_trace_given_top(JavaThread* thd,
383 ASGCT_CallTrace* trace,
384 int depth,
385 frame top_frame) {
386 NoHandleMark nhm;
387
388 frame initial_Java_frame;
389 Method* method;
390 int bci;
391 int count;
392
393 count = 0;
394 assert(trace->frames != NULL, "trace->frames must be non-NULL");
395
396 bool fully_decipherable = find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
397
398 // The frame might not be walkable but still recovered a method
399 // (e.g. an nmethod with no scope info for the pc)
400
401 if (method == NULL) return;
402
403 if (!method->is_valid_method()) {
404 trace->num_frames = ticks_GC_active; // -2
405 return;
406 }
407
408 // We got a Java frame however it isn't fully decipherable
409 // so it won't necessarily be safe to use it for the
410 // initial frame in the vframe stream.
411
412 if (!fully_decipherable) {
413 // Take whatever method the top-frame decoder managed to scrape up.
414 // We look further at the top frame only if non-safepoint
415 // debugging information is available.
416 count++;
417 trace->num_frames = count;
418 trace->frames[0].method_id = method->find_jmethod_id_or_null();
419 if (!method->is_native()) {
420 trace->frames[0].lineno = bci;
421 } else {
422 trace->frames[0].lineno = -3;
423 }
424
425 if (!initial_Java_frame.safe_for_sender(thd)) return;
426
427 RegisterMap map(thd, false);
428 initial_Java_frame = initial_Java_frame.sender(&map);
429 }
430
431 vframeStreamForte st(thd, initial_Java_frame, false);
432
433 for (; !st.at_end() && count < depth; st.forte_next(), count++) {
434 bci = st.bci();
435 method = st.method();
436
437 if (!method->is_valid_method()) {
438 // we throw away everything we've gathered in this sample since
439 // none of it is safe
440 trace->num_frames = ticks_GC_active; // -2
441 return;
442 }
443
444 trace->frames[count].method_id = method->find_jmethod_id_or_null();
445 if (!method->is_native()) {
446 trace->frames[count].lineno = bci;
447 } else {
448 trace->frames[count].lineno = -3;
449 }
450 }
451 trace->num_frames = count;
452 return;
453 }
454
455
456 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
457 // on Linux X86, Solaris SPARC and Solaris X86.
458 //
459 // Async-safe version of GetCallTrace being called from a signal handler
460 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
461 // with different content (see below).
462 //
463 // This function must only be called when JVM/TI
464 // CLASS_LOAD events have been enabled since agent startup. The enabled
465 // event will cause the jmethodIDs to be allocated at class load time.
466 // The jmethodIDs cannot be allocated in a signal handler because locks
467 // cannot be grabbed in a signal handler safely.
468 //
469 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
470 //
471 // Called by the profiler to obtain the current method call stack trace for
472 // a given thread. The thread is identified by the env_id field in the
473 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
474 // structure with enough memory for the requested stack depth. The VM fills in
475 // the frames buffer and the num_frames field.
476 //
477 // Arguments:
478 //
479 // trace - trace data structure to be filled by the VM.
480 // depth - depth of the call stack trace.
481 // ucontext - ucontext_t of the LWP
482 //
483 // ASGCT_CallTrace:
484 // typedef struct {
485 // JNIEnv *env_id;
486 // jint num_frames;
487 // ASGCT_CallFrame *frames;
488 // } ASGCT_CallTrace;
489 //
490 // Fields:
491 // env_id - ID of thread which executed this trace.
492 // num_frames - number of frames in the trace.
493 // (< 0 indicates the frame is not walkable).
494 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
495 //
496 // ASGCT_CallFrame:
497 // typedef struct {
498 // jint lineno;
499 // jmethodID method_id;
500 // } ASGCT_CallFrame;
501 //
502 // Fields:
503 // 1) For Java frame (interpreted and compiled),
504 // lineno - bci of the method being executed or -1 if bci is not available
505 // method_id - jmethodID of the method being executed
506 // 2) For native method
507 // lineno - (-3)
508 // method_id - jmethodID of the method being executed
509
510 extern "C" {
511 JNIEXPORT
512 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
513 JavaThread* thread;
514
515 if (trace->env_id == NULL ||
516 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
517 thread->is_exiting()) {
518
519 // bad env_id, thread has exited or thread is exiting
520 trace->num_frames = ticks_thread_exit; // -8
521 return;
522 }
523
524 if (thread->in_deopt_handler()) {
525 // thread is in the deoptimization handler so return no frames
526 trace->num_frames = ticks_deopt; // -9
527 return;
528 }
529
530 assert(JavaThread::current() == thread,
531 "AsyncGetCallTrace must be called by the current interrupted thread");
532
533 if (!JvmtiExport::should_post_class_load()) {
534 trace->num_frames = ticks_no_class_load; // -1
535 return;
536 }
537
538 if (Universe::heap()->is_gc_active()) {
539 trace->num_frames = ticks_GC_active; // -2
540 return;
541 }
542
543 switch (thread->thread_state()) {
544 case _thread_new:
545 case _thread_uninitialized:
546 case _thread_new_trans:
547 // We found the thread on the threads list above, but it is too
548 // young to be useful so return that there are no Java frames.
549 trace->num_frames = 0;
550 break;
551 case _thread_in_native:
552 case _thread_in_native_trans:
553 case _thread_blocked:
554 case _thread_blocked_trans:
555 case _thread_in_vm:
556 case _thread_in_vm_trans:
557 {
558 frame fr;
559
560 // param isInJava == false - indicate we aren't in Java code
561 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
562 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
563 } else {
564 if (!thread->has_last_Java_frame()) {
565 trace->num_frames = 0; // No Java frames
566 } else {
567 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
568 forte_fill_call_trace_given_top(thread, trace, depth, fr);
569
570 // This assert would seem to be valid but it is not.
571 // It would be valid if we weren't possibly racing a gc
572 // thread. A gc thread can make a valid interpreted frame
573 // look invalid. It's a small window but it does happen.
574 // The assert is left here commented out as a reminder.
575 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
576
577 }
578 }
579 }
580 break;
581 case _thread_in_Java:
582 case _thread_in_Java_trans:
583 {
584 frame fr;
585
586 // param isInJava == true - indicate we are in Java code
587 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
588 trace->num_frames = ticks_unknown_Java; // -5 unknown frame
589 } else {
590 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
591 forte_fill_call_trace_given_top(thread, trace, depth, fr);
592 }
593 }
594 break;
595 default:
596 // Unknown thread state
597 trace->num_frames = ticks_unknown_state; // -7
598 break;
599 }
600 }
601
602
603 #ifndef _WINDOWS
604 // Support for the Forte(TM) Peformance Tools collector.
605 //
606 // The method prototype is derived from libcollector.h. For more
607 // information, please see the libcollect man page.
608
609 // Method to let libcollector know about a dynamically loaded function.
610 // Because it is weakly bound, the calls become NOP's when the library
611 // isn't present.
612 #ifdef __APPLE__
613 // XXXDARWIN: Link errors occur even when __attribute__((weak_import))
614 // is added
615 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) ((void) 0)
616 #else
617 void collector_func_load(char* name,
618 void* null_argument_1,
619 void* null_argument_2,
620 void *vaddr,
621 int size,
622 int zero_argument,
623 void* null_argument_3);
624 #pragma weak collector_func_load
625 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
626 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 )
627 #endif // __APPLE__
628 #endif // !_WINDOWS
629
630 } // end extern "C"
631 #endif // !IA64 && !PPC64
632
633 void Forte::register_stub(const char* name, address start, address end) {
634 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64)
635 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
636 "Code size exceeds maximum range");
637
638 collector_func_load((char*)name, NULL, NULL, start,
639 pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
640 #endif // !_WINDOWS && !IA64 && !PPC64
641 }
642
643 #else // INCLUDE_JVMTI
644 extern "C" {
645 JNIEXPORT
646 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
647 trace->num_frames = ticks_no_class_load; // -1
648 }
649 }
650 #endif // INCLUDE_JVMTI