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