1 /*
2 * Copyright (c) 2003, 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 "code/debugInfoRec.hpp"
27 #include "code/pcDesc.hpp"
28 #include "gc/shared/collectedHeap.inline.hpp"
29 #include "gc/shared/space.hpp"
30 #include "memory/universe.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "prims/forte.hpp"
33 #include "runtime/javaCalls.hpp"
34 #include "runtime/thread.inline.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 #if !defined(IA64) && !defined(PPC64)
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 is available for this PC.
175 //
176 // vframeStreamCommon::fill_from_frame() will decode the frame depending
177 // on the state of the thread.
178 //
179 // Case #1: If the thread is in Java (state == _thread_in_Java), then
180 // the vframeStreamCommon object will be filled as if the frame were a native
181 // compiled frame. Therefore, no debug information is needed.
182 //
183 // Case #2: If the thread is in any other state, then two steps will be performed:
184 // - if asserts are enabled, found_bad_method_frame() will be called and
185 // the assert in found_bad_method_frame() will be triggered;
186 // - if asserts are disabled, the vframeStreamCommon object will be filled
187 // as if it were a native compiled frame.
188 //
189 // Case (2) is similar to the way interpreter frames are processed in
190 // vframeStreamCommon::fill_from_interpreter_frame in case no valid BCI
191 // was found for an interpreted frame. If asserts are enabled, the assert
192 // in found_bad_method_frame() will be triggered. If asserts are disabled,
193 // the vframeStreamCommon object will be filled afterwards as if the
194 // interpreter were at the point of entering into the method.
195 return false;
196 }
197
198 // This PcDesc is useful however we must adjust the frame's pc
199 // so that the vframeStream lookups will use this same pc
200 fr->set_pc(pc_desc->real_pc(nm));
201 return true;
202 }
203
204
205 // Determine if 'fr' is a walkable interpreted frame. Returns false
206 // if it is not. *method_p, and *bci_p are not set when false is
207 // returned. *method_p is non-NULL if frame was executing a Java
208 // method. *bci_p is != -1 if a valid BCI in the Java method could
209 // be found.
210 // Note: this method returns true when a valid Java method is found
211 // even if a valid BCI cannot be found.
212
213 static bool is_decipherable_interpreted_frame(JavaThread* thread,
214 frame* fr,
215 Method** method_p,
216 int* bci_p) {
217 assert(fr->is_interpreted_frame(), "just checking");
218
219 // top frame is an interpreted frame
220 // check if it is walkable (i.e. valid Method* and valid bci)
221
222 // Because we may be racing a gc thread the method and/or bci
223 // of a valid interpreter frame may look bad causing us to
224 // fail the is_interpreted_frame_valid test. If the thread
225 // is in any of the following states we are assured that the
226 // frame is in fact valid and we must have hit the race.
227
228 JavaThreadState state = thread->thread_state();
229 bool known_valid = (state == _thread_in_native ||
230 state == _thread_in_vm ||
231 state == _thread_blocked );
232
233 if (known_valid || fr->is_interpreted_frame_valid(thread)) {
234
235 // The frame code should completely validate the frame so that
236 // references to Method* and bci are completely safe to access
237 // If they aren't the frame code should be fixed not this
238 // code. However since gc isn't locked out the values could be
239 // stale. This is a race we can never completely win since we can't
240 // lock out gc so do one last check after retrieving their values
241 // from the frame for additional safety
242
243 Method* method = fr->interpreter_frame_method();
244
245 // We've at least found a method.
246 // NOTE: there is something to be said for the approach that
247 // if we don't find a valid bci then the method is not likely
248 // a valid method. Then again we may have caught an interpreter
249 // frame in the middle of construction and the bci field is
250 // not yet valid.
251 if (!method->is_valid_method()) return false;
252 *method_p = method; // If the Method* found is invalid, it is
253 // ignored by forte_fill_call_trace_given_top().
254 // So set method_p only if the Method is valid.
255
256 address bcp = fr->interpreter_frame_bcp();
257 int bci = method->validate_bci_from_bcp(bcp);
258
259 // note: bci is set to -1 if not a valid bci
260 *bci_p = bci;
261 return true;
262 }
263
264 return false;
265 }
266
267
268 // Determine if a Java frame can be found starting with the frame 'fr'.
269 //
270 // Check the return value of find_initial_Java_frame and the value of
271 // 'method_p' to decide on how use the results returned by this method.
272 //
273 // If 'method_p' is not NULL, an initial Java frame has been found and
274 // the stack can be walked starting from that initial frame. In this case,
275 // 'method_p' points to the Method that the initial frame belongs to and
276 // the initial Java frame is returned in initial_frame_p.
277 //
278 // find_initial_Java_frame() returns true if a Method has been found (i.e.,
279 // 'method_p' is not NULL) and the initial frame that belongs to that Method
280 // is decipherable.
281 //
282 // A frame is considered to be decipherable:
283 //
284 // - if the frame is a compiled frame and a PCDesc is available;
285 //
286 // - if the frame is an interpreter frame that is valid or the thread is
287 // state (_thread_in_native || state == _thread_in_vm || state == _thread_blocked).
288 //
289 // Note that find_initial_Java_frame() can return false even if an initial
290 // Java method was found (e.g., there is no PCDesc available for the method).
291 //
292 // If 'method_p' is NULL, it was not possible to find a Java frame when
293 // walking the stack starting from 'fr'. In this case find_initial_Java_frame
294 // returns false.
295
296 static bool find_initial_Java_frame(JavaThread* thread,
297 frame* fr,
298 frame* initial_frame_p,
299 Method** method_p,
300 int* bci_p) {
301
302 // It is possible that for a frame containing an nmethod
303 // we can capture the method but no bci. If we get no
304 // bci the frame isn't walkable but the method is usable.
305 // Therefore we init the returned Method* to NULL so the
306 // caller can make the distinction.
307
308 *method_p = NULL;
309
310 // On the initial call to this method the frame we get may not be
311 // recognizable to us. This should only happen if we are in a JRT_LEAF
312 // or something called by a JRT_LEAF method.
313
314 frame candidate = *fr;
315
316 // If the starting frame we were given has no codeBlob associated with
317 // it see if we can find such a frame because only frames with codeBlobs
318 // are possible Java frames.
319
320 if (fr->cb() == NULL) {
321
322 // See if we can find a useful frame
323 int loop_count;
324 int loop_max = MaxJavaStackTraceDepth * 2;
325 RegisterMap map(thread, false);
326
327 for (loop_count = 0; loop_count < loop_max; loop_count++) {
328 if (!candidate.safe_for_sender(thread)) return false;
329 candidate = candidate.sender(&map);
330 if (candidate.cb() != NULL) break;
331 }
332 if (candidate.cb() == NULL) return false;
333 }
334
335 // We have a frame known to be in the codeCache
336 // We will hopefully be able to figure out something to do with it.
337 int loop_count;
338 int loop_max = MaxJavaStackTraceDepth * 2;
339 RegisterMap map(thread, false);
340
341 for (loop_count = 0; loop_count < loop_max; loop_count++) {
342
343 if (candidate.is_entry_frame()) {
344 // jcw is NULL if the java call wrapper couldn't be found
345 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread);
346 // If initial frame is frame from StubGenerator and there is no
347 // previous anchor, there are no java frames associated with a method
348 if (jcw == NULL || jcw->is_first_frame()) {
349 return false;
350 }
351 }
352
353 if (candidate.is_interpreted_frame()) {
354 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
355 *initial_frame_p = candidate;
356 return true;
357 }
358
359 // Hopefully we got some data
360 return false;
361 }
362
363 if (candidate.cb()->is_nmethod()) {
364
365 nmethod* nm = (nmethod*) candidate.cb();
366 *method_p = nm->method();
367
368 // If the frame is not decipherable, then the value of -1
369 // for the BCI is used to signal that no BCI is available.
370 // Furthermore, the method returns false in this case.
371 //
372 // If a decipherable frame is available, the BCI value will
373 // not be used.
374
375 *bci_p = -1;
376
377 *initial_frame_p = candidate;
378
379 // Native wrapper code is trivial to decode by vframeStream
380
381 if (nm->is_native_method()) return true;
382
383 // If the frame is not decipherable, then a PC was found
384 // that does not have a PCDesc from which a BCI can be obtained.
385 // Nevertheless, a Method was found.
386
387 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) {
388 return false;
389 }
390
391 // is_decipherable_compiled_frame may modify candidate's pc
392 *initial_frame_p = candidate;
393
394 assert(nm->pc_desc_at(candidate.pc()) != NULL, "debug information must be available if the frame is decipherable");
395
396 return true;
397 }
398
399 // Must be some stub frame that we don't care about
400
401 if (!candidate.safe_for_sender(thread)) return false;
402 candidate = candidate.sender(&map);
403
404 // If it isn't in the code cache something is wrong
405 // since once we find a frame in the code cache they
406 // all should be there.
407
408 if (candidate.cb() == NULL) return false;
409
410 }
411
412 return false;
413
414 }
415
416 static void forte_fill_call_trace_given_top(JavaThread* thd,
417 ASGCT_CallTrace* trace,
418 int depth,
419 frame top_frame) {
420 NoHandleMark nhm;
421
422 frame initial_Java_frame;
423 Method* method;
424 int bci = -1; // assume BCI is not available for method
425 // update with correct information if available
426 int count;
427
428 count = 0;
429 assert(trace->frames != NULL, "trace->frames must be non-NULL");
430
431 // Walk the stack starting from 'top_frame' and search for an initial Java frame.
432 find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
433
434 // Check if a Java Method has been found.
435 if (method == NULL) return;
436
437 if (!method->is_valid_method()) {
438 trace->num_frames = ticks_GC_active; // -2
439 return;
440 }
441
442 vframeStreamForte st(thd, initial_Java_frame, false);
443
444 for (; !st.at_end() && count < depth; st.forte_next(), count++) {
445 bci = st.bci();
446 method = st.method();
447
448 if (!method->is_valid_method()) {
449 // we throw away everything we've gathered in this sample since
450 // none of it is safe
451 trace->num_frames = ticks_GC_active; // -2
452 return;
453 }
454
455 trace->frames[count].method_id = method->find_jmethod_id_or_null();
456 if (!method->is_native()) {
457 trace->frames[count].lineno = bci;
458 } else {
459 trace->frames[count].lineno = -3;
460 }
461 }
462 trace->num_frames = count;
463 return;
464 }
465
466
467 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
468 // on Linux X86, Solaris SPARC and Solaris X86.
469 //
470 // Async-safe version of GetCallTrace being called from a signal handler
471 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
472 // with different content (see below).
473 //
474 // This function must only be called when JVM/TI
475 // CLASS_LOAD events have been enabled since agent startup. The enabled
476 // event will cause the jmethodIDs to be allocated at class load time.
477 // The jmethodIDs cannot be allocated in a signal handler because locks
478 // cannot be grabbed in a signal handler safely.
479 //
480 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
481 //
482 // Called by the profiler to obtain the current method call stack trace for
483 // a given thread. The thread is identified by the env_id field in the
484 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
485 // structure with enough memory for the requested stack depth. The VM fills in
486 // the frames buffer and the num_frames field.
487 //
488 // Arguments:
489 //
490 // trace - trace data structure to be filled by the VM.
491 // depth - depth of the call stack trace.
492 // ucontext - ucontext_t of the LWP
493 //
494 // ASGCT_CallTrace:
495 // typedef struct {
496 // JNIEnv *env_id;
497 // jint num_frames;
498 // ASGCT_CallFrame *frames;
499 // } ASGCT_CallTrace;
500 //
501 // Fields:
502 // env_id - ID of thread which executed this trace.
503 // num_frames - number of frames in the trace.
504 // (< 0 indicates the frame is not walkable).
505 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
506 //
507 // ASGCT_CallFrame:
508 // typedef struct {
509 // jint lineno;
510 // jmethodID method_id;
511 // } ASGCT_CallFrame;
512 //
513 // Fields:
514 // 1) For Java frame (interpreted and compiled),
515 // lineno - bci of the method being executed or -1 if bci is not available
516 // method_id - jmethodID of the method being executed
517 // 2) For native method
518 // lineno - (-3)
519 // method_id - jmethodID of the method being executed
520
521 extern "C" {
522 JNIEXPORT
523 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
524 JavaThread* thread;
525
526 if (trace->env_id == NULL ||
527 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
528 thread->is_exiting()) {
529
530 // bad env_id, thread has exited or thread is exiting
531 trace->num_frames = ticks_thread_exit; // -8
532 return;
533 }
534
535 if (thread->in_deopt_handler()) {
536 // thread is in the deoptimization handler so return no frames
537 trace->num_frames = ticks_deopt; // -9
538 return;
539 }
540
541 assert(JavaThread::current() == thread,
542 "AsyncGetCallTrace must be called by the current interrupted thread");
543
544 if (!JvmtiExport::should_post_class_load()) {
545 trace->num_frames = ticks_no_class_load; // -1
546 return;
547 }
548
549 if (Universe::heap()->is_gc_active()) {
550 trace->num_frames = ticks_GC_active; // -2
551 return;
552 }
553
554 switch (thread->thread_state()) {
555 case _thread_new:
556 case _thread_uninitialized:
557 case _thread_new_trans:
558 // We found the thread on the threads list above, but it is too
559 // young to be useful so return that there are no Java frames.
560 trace->num_frames = 0;
561 break;
562 case _thread_in_native:
563 case _thread_in_native_trans:
564 case _thread_blocked:
565 case _thread_blocked_trans:
566 case _thread_in_vm:
567 case _thread_in_vm_trans:
568 {
569 frame fr;
570
571 // param isInJava == false - indicate we aren't in Java code
572 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
573 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
574 } else {
575 if (!thread->has_last_Java_frame()) {
576 trace->num_frames = 0; // No Java frames
577 } else {
578 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
579 forte_fill_call_trace_given_top(thread, trace, depth, fr);
580
581 // This assert would seem to be valid but it is not.
582 // It would be valid if we weren't possibly racing a gc
583 // thread. A gc thread can make a valid interpreted frame
584 // look invalid. It's a small window but it does happen.
585 // The assert is left here commented out as a reminder.
586 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
587
588 }
589 }
590 }
591 break;
592 case _thread_in_Java:
593 case _thread_in_Java_trans:
594 {
595 frame fr;
596
597 // param isInJava == true - indicate we are in Java code
598 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
599 trace->num_frames = ticks_unknown_Java; // -5 unknown frame
600 } else {
601 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
602 forte_fill_call_trace_given_top(thread, trace, depth, fr);
603 }
604 }
605 break;
606 default:
607 // Unknown thread state
608 trace->num_frames = ticks_unknown_state; // -7
609 break;
610 }
611 }
612
613
614 #ifndef _WINDOWS
615 // Support for the Forte(TM) Peformance Tools collector.
616 //
617 // The method prototype is derived from libcollector.h. For more
618 // information, please see the libcollect man page.
619
620 // Method to let libcollector know about a dynamically loaded function.
621 // Because it is weakly bound, the calls become NOP's when the library
622 // isn't present.
623 #ifdef __APPLE__
624 // XXXDARWIN: Link errors occur even when __attribute__((weak_import))
625 // is added
626 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) ((void) 0)
627 #else
628 void collector_func_load(char* name,
629 void* null_argument_1,
630 void* null_argument_2,
631 void *vaddr,
632 int size,
633 int zero_argument,
634 void* null_argument_3);
635 #pragma weak collector_func_load
636 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
637 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 )
638 #endif // __APPLE__
639 #endif // !_WINDOWS
640
641 } // end extern "C"
642 #endif // !IA64 && !PPC64
643
644 void Forte::register_stub(const char* name, address start, address end) {
645 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64)
646 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
647 "Code size exceeds maximum range");
648
649 collector_func_load((char*)name, NULL, NULL, start,
650 pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
651 #endif // !_WINDOWS && !IA64 && !PPC64
652 }
653
654 #else // INCLUDE_JVMTI
655 extern "C" {
656 JNIEXPORT
657 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
658 trace->num_frames = ticks_no_class_load; // -1
659 }
660 }
661 #endif // INCLUDE_JVMTI