1 /*
2 * Copyright (c) 2003, 2013, 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 is available for this PC.
176 //
177 // vframeStreamCommon::fill_from_frame() will decode the frame depending
178 // on the state of the thread.
179 //
180 // Case #1: If the thread is in Java (state == _thread_in_Java), then
181 // the vframeStreamCommon object will be filled as if the frame were a native
182 // compiled frame. Therefore, no debug information is needed.
183 //
184 // Case #2: If the thread is in any other state, then two steps will be performed:
185 // - if asserts are enabled, found_bad_method_frame() will be called and
186 // the assert in found_bad_method_frame() will be triggered;
187 // - if asserts are disabled, the vframeStreamCommon object will be filled
188 // as if it were a native compiled frame.
189 //
190 // Case (2) is similar to the way interpreter frames are processed in
191 // vframeStreamCommon::fill_from_interpreter_frame in case no valid BCI
192 // was found for an interpreted frame. If asserts are enabled, the assert
193 // in found_bad_method_frame() will be triggered. If asserts are disabled,
194 // the vframeStreamCommon object will be filled afterwards as if the
195 // interpreter were at the point of entering into the method.
196 return false;
197 }
198
199 // This PcDesc is useful however we must adjust the frame's pc
200 // so that the vframeStream lookups will use this same pc
201 fr->set_pc(thread, pc_desc->real_pc(nm));
202 return true;
203 }
204
205
206 // Determine if 'fr' is a walkable interpreted frame. Returns false
207 // if it is not. *method_p, and *bci_p are not set when false is
208 // returned. *method_p is non-NULL if frame was executing a Java
209 // method. *bci_p is != -1 if a valid BCI in the Java method could
210 // be found.
211 // Note: this method returns true when a valid Java method is found
212 // even if a valid BCI cannot be found.
213
214 static bool is_decipherable_interpreted_frame(JavaThread* thread,
215 frame* fr,
216 Method** method_p,
217 int* bci_p) {
218 assert(fr->is_interpreted_frame(), "just checking");
219
220 // top frame is an interpreted frame
221 // check if it is walkable (i.e. valid Method* and valid bci)
222
223 // Because we may be racing a gc thread the method and/or bci
224 // of a valid interpreter frame may look bad causing us to
225 // fail the is_interpreted_frame_valid test. If the thread
226 // is in any of the following states we are assured that the
227 // frame is in fact valid and we must have hit the race.
228
229 JavaThreadState state = thread->thread_state();
230 bool known_valid = (state == _thread_in_native ||
231 state == _thread_in_vm ||
232 state == _thread_blocked );
233
234 if (known_valid || fr->is_interpreted_frame_valid(thread)) {
235
236 // The frame code should completely validate the frame so that
237 // references to Method* and bci are completely safe to access
238 // If they aren't the frame code should be fixed not this
239 // code. However since gc isn't locked out the values could be
240 // stale. This is a race we can never completely win since we can't
241 // lock out gc so do one last check after retrieving their values
242 // from the frame for additional safety
243
244 Method* method = fr->interpreter_frame_method();
245
246 // We've at least found a method.
247 // NOTE: there is something to be said for the approach that
248 // if we don't find a valid bci then the method is not likely
249 // a valid method. Then again we may have caught an interpreter
250 // frame in the middle of construction and the bci field is
251 // not yet valid.
252 if (!method->is_valid_method()) return false;
253 *method_p = method; // If the Method* found is invalid, it is
254 // ignored by forte_fill_call_trace_given_top().
255 // So set method_p only if the Method is valid.
256
257 intptr_t bcx = fr->interpreter_frame_bcx();
258
259 int bci = method->validate_bci_from_bcx(bcx);
260
261 // note: bci is set to -1 if not a valid bci
262 *bci_p = bci;
263 return true;
264 }
265
266 return false;
267 }
268
269
270 // Determine if a Java frame can be found starting with the frame 'fr'.
271 //
272 // Check the return value of find_initial_Java_frame and the value of
273 // 'method_p' to decide on how use the results returned by this method.
274 //
275 // If 'method_p' is not NULL, an initial Java frame has been found and
276 // the stack can be walked starting from that initial frame. In this case,
277 // 'method_p' points to the Method that the initial frame belongs to and
278 // the initial Java frame is returned in initial_frame_p.
279 //
280 // find_initial_Java_frame() returns true if a Method has been found (i.e.,
281 // 'method_p' is not NULL) and the initial frame that belongs to that Method
282 // is decipherable.
283 //
284 // A frame is considered to be decipherable:
285 //
286 // - if the frame is a compiled frame and a PCDesc is available;
287 //
288 // - if the frame is an interpreter frame that is valid or the thread is
289 // state (_thread_in_native || state == _thread_in_vm || state == _thread_blocked).
290 //
291 // Note that find_initial_Java_frame() can return false even if an initial
292 // Java method was found (e.g., there is no PCDesc available for the method).
293 //
294 // If 'method_p' is NULL, it was not possible to find a Java frame when
295 // walking the stack starting from 'fr'. In this case find_initial_Java_frame
296 // returns false.
297
298 static bool find_initial_Java_frame(JavaThread* thread,
299 frame* fr,
300 frame* initial_frame_p,
301 Method** method_p,
302 int* bci_p) {
303
304 // It is possible that for a frame containing an nmethod
305 // we can capture the method but no bci. If we get no
306 // bci the frame isn't walkable but the method is usable.
307 // Therefore we init the returned Method* to NULL so the
308 // caller can make the distinction.
309
310 *method_p = NULL;
311
312 // On the initial call to this method the frame we get may not be
313 // recognizable to us. This should only happen if we are in a JRT_LEAF
314 // or something called by a JRT_LEAF method.
315
316 frame candidate = *fr;
317
318 // If the starting frame we were given has no codeBlob associated with
319 // it see if we can find such a frame because only frames with codeBlobs
320 // are possible Java frames.
321
322 if (fr->cb() == NULL) {
323
324 // See if we can find a useful frame
325 int loop_count;
326 int loop_max = MaxJavaStackTraceDepth * 2;
327 RegisterMap map(thread, false);
328
329 for (loop_count = 0; loop_count < loop_max; loop_count++) {
330 if (!candidate.safe_for_sender(thread)) return false;
331 candidate = candidate.sender(&map);
332 if (candidate.cb() != NULL) break;
333 }
334 if (candidate.cb() == NULL) return false;
335 }
336
337 // We have a frame known to be in the codeCache
338 // We will hopefully be able to figure out something to do with it.
339 int loop_count;
340 int loop_max = MaxJavaStackTraceDepth * 2;
341 RegisterMap map(thread, false);
342
343 for (loop_count = 0; loop_count < loop_max; loop_count++) {
344
345 if (candidate.is_entry_frame()) {
346 // jcw is NULL if the java call wrapper couldn't be found
347 JavaCallWrapper *jcw = candidate.entry_frame_call_wrapper_if_safe(thread);
348 // If initial frame is frame from StubGenerator and there is no
349 // previous anchor, there are no java frames associated with a method
350 if (jcw == NULL || jcw->is_first_frame()) {
351 return false;
352 }
353 }
354
355 if (candidate.is_interpreted_frame()) {
356 if (is_decipherable_interpreted_frame(thread, &candidate, method_p, bci_p)) {
357 *initial_frame_p = candidate;
358 return true;
359 }
360
361 // Hopefully we got some data
362 return false;
363 }
364
365 if (candidate.cb()->is_nmethod()) {
366
367 nmethod* nm = (nmethod*) candidate.cb();
368 *method_p = nm->method();
369
370 // If the frame is not decipherable, then the value of -1
371 // for the BCI is used to signal that no BCI is available.
372 // Furthermore, the method returns false in this case.
373 //
374 // If a decipherable frame is available, the BCI value will
375 // not be used.
376
377 *bci_p = -1;
378
379 *initial_frame_p = candidate;
380
381 // Native wrapper code is trivial to decode by vframeStream
382
383 if (nm->is_native_method()) return true;
384
385 // If the frame is not decipherable, then a PC was found
386 // that does not have a PCDesc from which a BCI can be obtained.
387 // Nevertheless, a Method was found.
388
389 if (!is_decipherable_compiled_frame(thread, &candidate, nm)) {
390 return false;
391 }
392
393 // is_decipherable_compiled_frame may modify candidate's pc
394 *initial_frame_p = candidate;
395
396 assert(nm->pc_desc_at(candidate.pc()) != NULL, "debug information must be available if the frame is decipherable");
397
398 return true;
399 }
400
401 // Must be some stub frame that we don't care about
402
403 if (!candidate.safe_for_sender(thread)) return false;
404 candidate = candidate.sender(&map);
405
406 // If it isn't in the code cache something is wrong
407 // since once we find a frame in the code cache they
408 // all should be there.
409
410 if (candidate.cb() == NULL) return false;
411
412 }
413
414 return false;
415
416 }
417
418 static void forte_fill_call_trace_given_top(JavaThread* thd,
419 ASGCT_CallTrace* trace,
420 int depth,
421 frame top_frame) {
422 NoHandleMark nhm;
423
424 frame initial_Java_frame;
425 Method* method;
426 int bci = -1; // assume BCI is not available for method
427 // update with correct information if available
428 int count;
429
430 count = 0;
431 assert(trace->frames != NULL, "trace->frames must be non-NULL");
432
433 // Walk the stack starting from 'top_frame' and search for an initial Java frame.
434 find_initial_Java_frame(thd, &top_frame, &initial_Java_frame, &method, &bci);
435
436 // Check if a Java Method has been found.
437 if (method == NULL) return;
438
439 if (!method->is_valid_method()) {
440 trace->num_frames = ticks_GC_active; // -2
441 return;
442 }
443
444 vframeStreamForte st(thd, initial_Java_frame, false);
445
446 for (; !st.at_end() && count < depth; st.forte_next(), count++) {
447 bci = st.bci();
448 method = st.method();
449
450 if (!method->is_valid_method()) {
451 // we throw away everything we've gathered in this sample since
452 // none of it is safe
453 trace->num_frames = ticks_GC_active; // -2
454 return;
455 }
456
457 trace->frames[count].method_id = method->find_jmethod_id_or_null();
458 if (!method->is_native()) {
459 trace->frames[count].lineno = bci;
460 } else {
461 trace->frames[count].lineno = -3;
462 }
463 }
464 trace->num_frames = count;
465 return;
466 }
467
468
469 // Forte Analyzer AsyncGetCallTrace() entry point. Currently supported
470 // on Linux X86, Solaris SPARC and Solaris X86.
471 //
472 // Async-safe version of GetCallTrace being called from a signal handler
473 // when a LWP gets interrupted by SIGPROF but the stack traces are filled
474 // with different content (see below).
475 //
476 // This function must only be called when JVM/TI
477 // CLASS_LOAD events have been enabled since agent startup. The enabled
478 // event will cause the jmethodIDs to be allocated at class load time.
479 // The jmethodIDs cannot be allocated in a signal handler because locks
480 // cannot be grabbed in a signal handler safely.
481 //
482 // void (*AsyncGetCallTrace)(ASGCT_CallTrace *trace, jint depth, void* ucontext)
483 //
484 // Called by the profiler to obtain the current method call stack trace for
485 // a given thread. The thread is identified by the env_id field in the
486 // ASGCT_CallTrace structure. The profiler agent should allocate a ASGCT_CallTrace
487 // structure with enough memory for the requested stack depth. The VM fills in
488 // the frames buffer and the num_frames field.
489 //
490 // Arguments:
491 //
492 // trace - trace data structure to be filled by the VM.
493 // depth - depth of the call stack trace.
494 // ucontext - ucontext_t of the LWP
495 //
496 // ASGCT_CallTrace:
497 // typedef struct {
498 // JNIEnv *env_id;
499 // jint num_frames;
500 // ASGCT_CallFrame *frames;
501 // } ASGCT_CallTrace;
502 //
503 // Fields:
504 // env_id - ID of thread which executed this trace.
505 // num_frames - number of frames in the trace.
506 // (< 0 indicates the frame is not walkable).
507 // frames - the ASGCT_CallFrames that make up this trace. Callee followed by callers.
508 //
509 // ASGCT_CallFrame:
510 // typedef struct {
511 // jint lineno;
512 // jmethodID method_id;
513 // } ASGCT_CallFrame;
514 //
515 // Fields:
516 // 1) For Java frame (interpreted and compiled),
517 // lineno - bci of the method being executed or -1 if bci is not available
518 // method_id - jmethodID of the method being executed
519 // 2) For native method
520 // lineno - (-3)
521 // method_id - jmethodID of the method being executed
522
523 extern "C" {
524 JNIEXPORT
525 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
526 JavaThread* thread;
527
528 if (trace->env_id == NULL ||
529 (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
530 thread->is_exiting()) {
531
532 // bad env_id, thread has exited or thread is exiting
533 trace->num_frames = ticks_thread_exit; // -8
534 return;
535 }
536
537 if (thread->in_deopt_handler()) {
538 // thread is in the deoptimization handler so return no frames
539 trace->num_frames = ticks_deopt; // -9
540 return;
541 }
542
543 assert(JavaThread::current() == thread,
544 "AsyncGetCallTrace must be called by the current interrupted thread");
545
546 if (!JvmtiExport::should_post_class_load()) {
547 trace->num_frames = ticks_no_class_load; // -1
548 return;
549 }
550
551 if (Universe::heap()->is_gc_active()) {
552 trace->num_frames = ticks_GC_active; // -2
553 return;
554 }
555
556 switch (thread->thread_state()) {
557 case _thread_new:
558 case _thread_uninitialized:
559 case _thread_new_trans:
560 // We found the thread on the threads list above, but it is too
561 // young to be useful so return that there are no Java frames.
562 trace->num_frames = 0;
563 break;
564 case _thread_in_native:
565 case _thread_in_native_trans:
566 case _thread_blocked:
567 case _thread_blocked_trans:
568 case _thread_in_vm:
569 case _thread_in_vm_trans:
570 {
571 frame fr;
572
573 // param isInJava == false - indicate we aren't in Java code
574 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
575 trace->num_frames = ticks_unknown_not_Java; // -3 unknown frame
576 } else {
577 if (!thread->has_last_Java_frame()) {
578 trace->num_frames = 0; // No Java frames
579 } else {
580 trace->num_frames = ticks_not_walkable_not_Java; // -4 non walkable frame by default
581 forte_fill_call_trace_given_top(thread, trace, depth, fr);
582
583 // This assert would seem to be valid but it is not.
584 // It would be valid if we weren't possibly racing a gc
585 // thread. A gc thread can make a valid interpreted frame
586 // look invalid. It's a small window but it does happen.
587 // The assert is left here commented out as a reminder.
588 // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");
589
590 }
591 }
592 }
593 break;
594 case _thread_in_Java:
595 case _thread_in_Java_trans:
596 {
597 frame fr;
598
599 // param isInJava == true - indicate we are in Java code
600 if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
601 trace->num_frames = ticks_unknown_Java; // -5 unknown frame
602 } else {
603 trace->num_frames = ticks_not_walkable_Java; // -6, non walkable frame by default
604 forte_fill_call_trace_given_top(thread, trace, depth, fr);
605 }
606 }
607 break;
608 default:
609 // Unknown thread state
610 trace->num_frames = ticks_unknown_state; // -7
611 break;
612 }
613 }
614
615
616 #ifndef _WINDOWS
617 // Support for the Forte(TM) Peformance Tools collector.
618 //
619 // The method prototype is derived from libcollector.h. For more
620 // information, please see the libcollect man page.
621
622 // Method to let libcollector know about a dynamically loaded function.
623 // Because it is weakly bound, the calls become NOP's when the library
624 // isn't present.
625 #ifdef __APPLE__
626 // XXXDARWIN: Link errors occur even when __attribute__((weak_import))
627 // is added
628 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) (0)
629 #else
630 void collector_func_load(char* name,
631 void* null_argument_1,
632 void* null_argument_2,
633 void *vaddr,
634 int size,
635 int zero_argument,
636 void* null_argument_3);
637 #pragma weak collector_func_load
638 #define collector_func_load(x0,x1,x2,x3,x4,x5,x6) \
639 ( collector_func_load ? collector_func_load(x0,x1,x2,x3,x4,x5,x6),(void)0 : (void)0 )
640 #endif // __APPLE__
641 #endif // !_WINDOWS
642
643 } // end extern "C"
644 #endif // !IA64 && !PPC64
645
646 void Forte::register_stub(const char* name, address start, address end) {
647 #if !defined(_WINDOWS) && !defined(IA64) && !defined(PPC64)
648 assert(pointer_delta(end, start, sizeof(jbyte)) < INT_MAX,
649 "Code size exceeds maximum range");
650
651 collector_func_load((char*)name, NULL, NULL, start,
652 pointer_delta(end, start, sizeof(jbyte)), 0, NULL);
653 #endif // !_WINDOWS && !IA64 && !PPC64
654 }
655
656 #else // INCLUDE_JVMTI
657 extern "C" {
658 JNIEXPORT
659 void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
660 trace->num_frames = ticks_no_class_load; // -1
661 }
662 }
663 #endif // INCLUDE_JVMTI