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