1 /*
2 * Copyright (c) 2018, 2020, Red Hat, Inc. 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
26 #include "gc/shenandoah/shenandoahAsserts.hpp"
27 #include "gc/shenandoah/shenandoahForwarding.hpp"
28 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
29 #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
30 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
31 #include "gc/shenandoah/shenandoahUtils.hpp"
32 #include "memory/resourceArea.hpp"
33
34 void print_raw_memory(ShenandoahMessageBuffer &msg, void* loc) {
35 // Be extra safe. Only access data that is guaranteed to be safe:
36 // should be in heap, in known committed region, within that region.
37
38 ShenandoahHeap* heap = ShenandoahHeap::heap();
39 if (!heap->is_in_reserved(loc)) return;
40
41 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
42 if (r != nullptr && r->is_committed()) {
43 address start = MAX2((address) r->bottom(), (address) loc - 32);
44 address end = MIN2((address) r->end(), (address) loc + 128);
45 if (start >= end) return;
46
47 stringStream ss;
48 os::print_hex_dump(&ss, start, end, 4);
49 msg.append("\n");
50 msg.append("Raw heap memory:\n%s", ss.freeze());
51 }
52 }
53
54 void ShenandoahAsserts::print_obj(ShenandoahMessageBuffer& msg, oop obj) {
55 ShenandoahHeap* heap = ShenandoahHeap::heap();
56 ShenandoahHeapRegion *r = heap->heap_region_containing(obj);
57
58 ResourceMark rm;
59 stringStream ss;
60 r->print_on(&ss);
61
62 stringStream mw_ss;
63 obj->mark().print_on(&mw_ss);
64
65 ShenandoahMarkingContext* const ctx = heap->marking_context();
66
67 msg.append(" " PTR_FORMAT " - klass " PTR_FORMAT " %s\n", p2i(obj), p2i(obj->klass()), obj->klass()->external_name());
68 msg.append(" %3s allocated after mark start\n", ctx->allocated_after_mark_start(obj) ? "" : "not");
69 msg.append(" %3s after update watermark\n", cast_from_oop<HeapWord*>(obj) >= r->get_update_watermark() ? "" : "not");
70 msg.append(" %3s marked strong\n", ctx->is_marked_strong(obj) ? "" : "not");
71 msg.append(" %3s marked weak\n", ctx->is_marked_weak(obj) ? "" : "not");
72 msg.append(" %3s in collection set\n", heap->in_collection_set(obj) ? "" : "not");
73 if (heap->mode()->is_generational() && !obj->is_forwarded()) {
74 msg.append(" age: %d\n", obj->age());
75 }
76 msg.append(" mark:%s\n", mw_ss.freeze());
77 msg.append(" region: %s", ss.freeze());
78 }
79
80 void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) {
81 ShenandoahHeap* heap = ShenandoahHeap::heap();
82 if (heap->is_in_reserved(loc)) {
83 msg.append(" inside Java heap\n");
84 ShenandoahHeapRegion *r = heap->heap_region_containing(loc);
85 stringStream ss;
86 r->print_on(&ss);
87
88 msg.append(" %3s in collection set\n", heap->in_collection_set_loc(loc) ? "" : "not");
89 msg.append(" region: %s", ss.freeze());
90 } else {
91 msg.append(" outside of Java heap\n");
92 stringStream ss;
93 os::print_location(&ss, (intptr_t) loc, false);
94 msg.append(" %s", ss.freeze());
95 }
96 }
97
98 void ShenandoahAsserts::print_obj_safe(ShenandoahMessageBuffer& msg, void* loc) {
99 ShenandoahHeap* heap = ShenandoahHeap::heap();
100 msg.append(" " PTR_FORMAT " - safe print, no details\n", p2i(loc));
101 if (heap->is_in_reserved(loc)) {
102 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
103 if (r != nullptr) {
104 stringStream ss;
105 r->print_on(&ss);
106 msg.append(" region: %s", ss.freeze());
107 print_raw_memory(msg, loc);
108 }
109 }
110 }
111
112 void ShenandoahAsserts::print_failure(SafeLevel level, oop obj, void* interior_loc, oop loc,
113 const char* phase, const char* label,
114 const char* file, int line) {
115 ShenandoahHeap* heap = ShenandoahHeap::heap();
116 ResourceMark rm;
117
118 bool loc_in_heap = (loc != nullptr && heap->is_in_reserved(loc));
119
120 ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label);
121
122 msg.append("Referenced from:\n");
123 if (interior_loc != nullptr) {
124 msg.append(" interior location: " PTR_FORMAT "\n", p2i(interior_loc));
125 if (loc_in_heap) {
126 print_obj(msg, loc);
127 } else {
128 print_non_obj(msg, interior_loc);
129 }
130 } else {
131 msg.append(" no interior location recorded (probably a plain heap scan, or detached oop)\n");
132 }
133 msg.append("\n");
134
135 msg.append("Object:\n");
136 if (level >= _safe_oop) {
137 print_obj(msg, obj);
138 } else {
139 print_obj_safe(msg, obj);
140 }
141 msg.append("\n");
142
143 if (level >= _safe_oop) {
144 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
145 msg.append("Forwardee:\n");
146 if (obj != fwd) {
147 if (level >= _safe_oop_fwd) {
148 print_obj(msg, fwd);
149 } else {
150 print_obj_safe(msg, fwd);
151 }
152 } else {
153 msg.append(" (the object itself)");
154 }
155 msg.append("\n");
156 }
157
158 if (level >= _safe_oop_fwd) {
159 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
160 oop fwd2 = ShenandoahForwarding::get_forwardee_raw_unchecked(fwd);
161 if (fwd != fwd2) {
162 msg.append("Second forwardee:\n");
163 print_obj_safe(msg, fwd2);
164 msg.append("\n");
165 }
166 }
167
168 report_vm_error(file, line, msg.buffer());
169 }
170
171 void ShenandoahAsserts::assert_in_heap_bounds(void* interior_loc, oop obj, const char *file, int line) {
172 ShenandoahHeap* heap = ShenandoahHeap::heap();
173
174 if (!heap->is_in_reserved(obj)) {
175 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_heap_bounds failed",
176 "oop must be in heap bounds",
177 file, line);
178 }
179 }
180
181 void ShenandoahAsserts::assert_in_heap_bounds_or_null(void* interior_loc, oop obj, const char *file, int line) {
182 ShenandoahHeap* heap = ShenandoahHeap::heap();
183
184 if (obj != nullptr && !heap->is_in_reserved(obj)) {
185 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_heap_bounds_or_null failed",
186 "oop must be in heap bounds",
187 file, line);
188 }
189 }
190
191 void ShenandoahAsserts::assert_correct(void* interior_loc, oop obj, const char* file, int line) {
192 ShenandoahHeap* heap = ShenandoahHeap::heap();
193
194 // Step 1. Check that obj is correct.
195 // After this step, it is safe to call heap_region_containing().
196 if (!heap->is_in_reserved(obj)) {
197 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
198 "oop must be in heap bounds",
199 file, line);
200 }
201
202 Klass* obj_klass = ShenandoahForwarding::klass(obj);
203 if (obj_klass == nullptr) {
204 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
205 "Object klass pointer should not be null",
206 file,line);
207 }
208
209 if (!Metaspace::contains(obj_klass)) {
210 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
211 "Object klass pointer must go to metaspace",
212 file,line);
213 }
214
215 if (!heap->is_in(obj)) {
216 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
217 "Object should be in active region area",
218 file, line);
219 }
220
221 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
222
223 if (obj != fwd) {
224 // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
225 // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
226 // that still points to the object itself.
227 if (heap->is_full_gc_move_in_progress()) {
228 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
229 "Non-trivial forwarding pointer during Full GC moves, probable bug.",
230 file, line);
231 }
232
233 // Step 2. Check that forwardee is correct
234 if (!heap->is_in_reserved(fwd)) {
235 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
236 "Forwardee must be in heap bounds",
237 file, line);
238 }
239
240 if (obj_klass != ShenandoahForwarding::klass(fwd)) {
241 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
242 "Forwardee klass disagrees with object class",
243 file, line);
244 }
245
246 // Step 3. Check that forwardee points to correct region
247 if (!heap->is_in(fwd)) {
248 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
249 "Forwardee should be in active region area",
250 file, line);
251 }
252
253 if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
254 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
255 "Non-trivial forwardee should be in another region",
256 file, line);
257 }
258
259 // Step 4. Check for multiple forwardings
260 oop fwd2 = ShenandoahForwarding::get_forwardee_raw_unchecked(fwd);
261 if (fwd != fwd2) {
262 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
263 "Multiple forwardings",
264 file, line);
265 }
266 }
267
268 // Do additional checks for special objects: their fields can hold metadata as well.
269 // We want to check class loading/unloading did not corrupt them.
270
271 if (Universe::is_fully_initialized() && (obj_klass == vmClasses::Class_klass())) {
272 Metadata* klass = obj->metadata_field(java_lang_Class::klass_offset());
273 if (klass != nullptr && !Metaspace::contains(klass)) {
274 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
275 "Instance class mirror should point to Metaspace",
276 file, line);
277 }
278
279 Metadata* array_klass = obj->metadata_field(java_lang_Class::array_klass_offset());
280 if (array_klass != nullptr && !Metaspace::contains(array_klass)) {
281 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed",
282 "Array class mirror should point to Metaspace",
283 file, line);
284 }
285 }
286 }
287
288 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
289 assert_correct(interior_loc, obj, file, line);
290
291 ShenandoahHeap* heap = ShenandoahHeap::heap();
292 ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
293 if (!r->is_active()) {
294 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed",
295 "Object must reside in active region",
296 file, line);
297 }
298
299 size_t alloc_size = obj->size();
300 HeapWord* obj_end = cast_from_oop<HeapWord*>(obj) + alloc_size;
301
302 if (ShenandoahHeapRegion::requires_humongous(alloc_size)) {
303 size_t idx = r->index();
304 size_t end_idx = heap->heap_region_index_containing(obj_end - 1);
305 for (size_t i = idx; i < end_idx; i++) {
306 ShenandoahHeapRegion* chain_reg = heap->get_region(i);
307 if (i == idx && !chain_reg->is_humongous_start()) {
308 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed",
309 "Object must reside in humongous start",
310 file, line);
311 }
312 if (i != idx && !chain_reg->is_humongous_continuation()) {
313 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed",
314 "Humongous continuation should be of proper size",
315 file, line);
316 }
317 }
318 } else {
319 if (obj_end > r->top()) {
320 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed",
321 "Object end should be within the active area of the region",
322 file, line);
323 }
324 }
325 }
326
327 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
328 assert_correct(interior_loc, obj, file, line);
329 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
330
331 if (obj == fwd) {
332 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_forwarded failed",
333 "Object should be forwarded",
334 file, line);
335 }
336 }
337
338 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
339 assert_correct(interior_loc, obj, file, line);
340 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
341
342 if (obj != fwd) {
343 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_not_forwarded failed",
344 "Object should not be forwarded",
345 file, line);
346 }
347 }
348
349 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
350 assert_correct(interior_loc, obj, file, line);
351
352 ShenandoahHeap* heap = ShenandoahHeap::heap();
353 if (!heap->marking_context()->is_marked(obj)) {
354 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked failed",
355 "Object should be marked",
356 file, line);
357 }
358 }
359
360 void ShenandoahAsserts::assert_marked_weak(void *interior_loc, oop obj, const char *file, int line) {
361 assert_correct(interior_loc, obj, file, line);
362
363 ShenandoahHeap* heap = ShenandoahHeap::heap();
364 if (!heap->marking_context()->is_marked_weak(obj)) {
365 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked_weak failed",
366 "Object should be marked weakly",
367 file, line);
368 }
369 }
370
371 void ShenandoahAsserts::assert_marked_strong(void *interior_loc, oop obj, const char *file, int line) {
372 assert_correct(interior_loc, obj, file, line);
373
374 ShenandoahHeap* heap = ShenandoahHeap::heap();
375 if (!heap->marking_context()->is_marked_strong(obj)) {
376 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked_strong failed",
377 "Object should be marked strongly",
378 file, line);
379 }
380 }
381
382 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
383 assert_correct(interior_loc, obj, file, line);
384
385 ShenandoahHeap* heap = ShenandoahHeap::heap();
386 if (!heap->in_collection_set(obj)) {
387 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_in_cset failed",
388 "Object should be in collection set",
389 file, line);
390 }
391 }
392
393 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
394 assert_correct(interior_loc, obj, file, line);
395
396 ShenandoahHeap* heap = ShenandoahHeap::heap();
397 if (heap->in_collection_set(obj)) {
398 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_not_in_cset failed",
399 "Object should not be in collection set",
400 file, line);
401 }
402 }
403
404 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
405 ShenandoahHeap* heap = ShenandoahHeap::heap();
406 if (heap->in_collection_set_loc(interior_loc)) {
407 print_failure(_safe_unknown, nullptr, interior_loc, nullptr, "Shenandoah assert_not_in_cset_loc failed",
408 "Interior location should not be in collection set",
409 file, line);
410 }
411 }
412
413 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
414 const char *file, int line) {
415 ShenandoahMessageBuffer msg("%s\n", label);
416 msg.append(" Actual: " PTR_FORMAT "\n", p2i(actual));
417 report_vm_error(file, line, msg.buffer());
418 }
419
420 void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(Mutex* lock, const char* file, int line) {
421 if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
422 return;
423 }
424
425 if (lock->owned_by_self()) {
426 return;
427 }
428
429 ShenandoahMessageBuffer msg("Must be at a Shenandoah safepoint or held %s lock", lock->name());
430 report_vm_error(file, line, msg.buffer());
431 }
432
433 void ShenandoahAsserts::assert_heaplocked(const char* file, int line) {
434 ShenandoahHeap* heap = ShenandoahHeap::heap();
435
436 if (heap->lock()->owned_by_self()) {
437 return;
438 }
439
440 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread");
441 report_vm_error(file, line, msg.buffer());
442 }
443
444 void ShenandoahAsserts::assert_not_heaplocked(const char* file, int line) {
445 ShenandoahHeap* heap = ShenandoahHeap::heap();
446
447 if (!heap->lock()->owned_by_self()) {
448 return;
449 }
450
451 ShenandoahMessageBuffer msg("Heap lock must not be owned by current thread");
452 report_vm_error(file, line, msg.buffer());
453 }
454
455 void ShenandoahAsserts::assert_heaplocked_or_safepoint(const char* file, int line) {
456 ShenandoahHeap* heap = ShenandoahHeap::heap();
457
458 if (heap->lock()->owned_by_self()) {
459 return;
460 }
461
462 if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
463 return;
464 }
465
466 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread, or be at safepoint");
467 report_vm_error(file, line, msg.buffer());
468 }
469
470 void ShenandoahAsserts::assert_generational(const char* file, int line) {
471 if (ShenandoahHeap::heap()->mode()->is_generational()) {
472 return;
473 }
474
475 ShenandoahMessageBuffer msg("Must be in generational mode");
476 report_vm_error(file, line, msg.buffer());
477 }
478
479 void ShenandoahAsserts::assert_control_or_vm_thread_at_safepoint(bool at_safepoint, const char* file, int line) {
480 Thread* thr = Thread::current();
481 if (thr == ShenandoahHeap::heap()->control_thread()) {
482 return;
483 }
484 if (thr->is_VM_thread()) {
485 if (!at_safepoint) {
486 return;
487 } else if (SafepointSynchronize::is_at_safepoint()) {
488 return;
489 }
490 }
491
492 ShenandoahMessageBuffer msg("Must be either control thread, or vm thread");
493 if (at_safepoint) {
494 msg.append(" at a safepoint");
495 }
496 report_vm_error(file, line, msg.buffer());
497 }
498
499 void ShenandoahAsserts::assert_generations_reconciled(const char* file, int line) {
500 if (!SafepointSynchronize::is_at_safepoint()) {
501 return;
502 }
503
504 ShenandoahHeap* heap = ShenandoahHeap::heap();
505 ShenandoahGeneration* ggen = heap->gc_generation();
506 ShenandoahGeneration* agen = heap->active_generation();
507 if (agen == ggen) {
508 return;
509 }
510
511 ShenandoahMessageBuffer msg("Active(%d) & GC(%d) Generations aren't reconciled", agen->type(), ggen->type());
512 report_vm_error(file, line, msg.buffer());
513 }