1 /*
2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "precompiled.hpp"
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(loc)) return;
40
41 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
42 if (r != NULL && 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.as_string());
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((HeapWord *) obj) ? "" : "not");
69 msg.append(" %3s marked \n", ctx->is_marked(obj) ? "" : "not");
70 msg.append(" %3s in collection set\n", heap->in_collection_set(obj) ? "" : "not");
71 msg.append(" mark:%s\n", mw_ss.as_string());
72 msg.append(" region: %s", ss.as_string());
73 }
74
75 void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) {
76 ShenandoahHeap* heap = ShenandoahHeap::heap();
77 if (heap->is_in(loc)) {
78 msg.append(" inside Java heap\n");
79 ShenandoahHeapRegion *r = heap->heap_region_containing(loc);
80 stringStream ss;
81 r->print_on(&ss);
82
83 msg.append(" %3s in collection set\n", heap->in_collection_set_loc(loc) ? "" : "not");
84 msg.append(" region: %s", ss.as_string());
85 } else {
86 msg.append(" outside of Java heap\n");
87 stringStream ss;
88 os::print_location(&ss, (intptr_t) loc, false);
89 msg.append(" %s", ss.as_string());
90 }
91 }
92
93 void ShenandoahAsserts::print_obj_safe(ShenandoahMessageBuffer& msg, void* loc) {
94 ShenandoahHeap* heap = ShenandoahHeap::heap();
95 msg.append(" " PTR_FORMAT " - safe print, no details\n", p2i(loc));
96 if (heap->is_in(loc)) {
97 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
98 if (r != NULL) {
99 stringStream ss;
100 r->print_on(&ss);
101 msg.append(" region: %s", ss.as_string());
102 print_raw_memory(msg, loc);
103 }
104 }
105 }
106
107 void ShenandoahAsserts::print_failure(SafeLevel level, oop obj, void* interior_loc, oop loc,
108 const char* phase, const char* label,
109 const char* file, int line) {
110 ShenandoahHeap* heap = ShenandoahHeap::heap();
111 ResourceMark rm;
112
113 bool loc_in_heap = (loc != NULL && heap->is_in(loc));
114
115 ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label);
116
117 msg.append("Referenced from:\n");
118 if (interior_loc != NULL) {
119 msg.append(" interior location: " PTR_FORMAT "\n", p2i(interior_loc));
120 if (loc_in_heap) {
121 print_obj(msg, loc);
122 } else {
123 print_non_obj(msg, interior_loc);
124 }
125 } else {
126 msg.append(" no interior location recorded (probably a plain heap scan, or detached oop)\n");
127 }
128 msg.append("\n");
129
130 msg.append("Object:\n");
131 if (level >= _safe_oop) {
132 print_obj(msg, obj);
133 } else {
134 print_obj_safe(msg, obj);
135 }
136 msg.append("\n");
137
138 if (level >= _safe_oop) {
139 oop fwd = (oop) ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
140 msg.append("Forwardee:\n");
141 if (obj != fwd) {
142 if (level >= _safe_oop_fwd) {
143 print_obj(msg, fwd);
144 } else {
145 print_obj_safe(msg, fwd);
146 }
147 } else {
148 msg.append(" (the object itself)");
149 }
150 msg.append("\n");
151 }
152
153 if (level >= _safe_oop_fwd) {
154 oop fwd = (oop) ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
155 oop fwd2 = (oop) ShenandoahForwarding::get_forwardee_raw_unchecked(fwd);
156 if (fwd != fwd2) {
157 msg.append("Second forwardee:\n");
158 print_obj_safe(msg, fwd2);
159 msg.append("\n");
160 }
161 }
162
163 report_vm_error(file, line, msg.buffer());
164 }
165
166 void ShenandoahAsserts::assert_in_heap(void* interior_loc, oop obj, const char *file, int line) {
167 ShenandoahHeap* heap = ShenandoahHeap::heap();
168
169 if (!heap->is_in(obj)) {
170 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap failed",
171 "oop must point to a heap address",
172 file, line);
173 }
174 }
175
176 void ShenandoahAsserts::assert_correct(void* interior_loc, oop obj, const char* file, int line) {
177 ShenandoahHeap* heap = ShenandoahHeap::heap();
178
179 // Step 1. Check that obj is correct.
180 // After this step, it is safe to call heap_region_containing().
181 if (!heap->is_in(obj)) {
182 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
183 "oop must point to a heap address",
184 file, line);
185 }
186
187 Klass* obj_klass = obj->klass_or_null();
188 if (obj_klass == NULL) {
189 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
190 "Object klass pointer should not be NULL",
191 file,line);
192 }
193
194 if (!Metaspace::contains(obj_klass)) {
195 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
196 "Object klass pointer must go to metaspace",
197 file,line);
198 }
199
200 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
201
202 if (obj != fwd) {
203 // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
204 // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
205 // that still points to the object itself.
206 if (heap->is_full_gc_move_in_progress()) {
207 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
208 "Non-trivial forwarding pointer during Full GC moves, probable bug.",
209 file, line);
210 }
211
212 // Step 2. Check that forwardee is correct
213 if (!heap->is_in(fwd)) {
214 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
215 "Forwardee must point to a heap address",
216 file, line);
217 }
218
219 if (obj_klass != fwd->klass()) {
220 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
221 "Forwardee klass disagrees with object class",
222 file, line);
223 }
224
225 // Step 3. Check that forwardee points to correct region
226 if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
227 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
228 "Non-trivial forwardee should in another region",
229 file, line);
230 }
231
232 // Step 4. Check for multiple forwardings
233 oop fwd2 = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(fwd));
234 if (fwd != fwd2) {
235 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
236 "Multiple forwardings",
237 file, line);
238 }
239 }
240 }
241
242 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
243 assert_correct(interior_loc, obj, file, line);
244
245 ShenandoahHeap* heap = ShenandoahHeap::heap();
246 ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
247 if (!r->is_active()) {
248 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
249 "Object must reside in active region",
250 file, line);
251 }
252
253 size_t alloc_size = obj->size();
254 if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
255 size_t idx = r->index();
256 size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
257 for (size_t i = idx; i < idx + num_regions; i++) {
258 ShenandoahHeapRegion* chain_reg = heap->get_region(i);
259 if (i == idx && !chain_reg->is_humongous_start()) {
260 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
261 "Object must reside in humongous start",
262 file, line);
263 }
264 if (i != idx && !chain_reg->is_humongous_continuation()) {
265 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
266 "Humongous continuation should be of proper size",
267 file, line);
268 }
269 }
270 }
271 }
272
273 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
274 assert_correct(interior_loc, obj, file, line);
275 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
276
277 if (obj == fwd) {
278 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
279 "Object should be forwarded",
280 file, line);
281 }
282 }
283
284 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
285 assert_correct(interior_loc, obj, file, line);
286 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
287
288 if (obj != fwd) {
289 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
290 "Object should not be forwarded",
291 file, line);
292 }
293 }
294
295 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
296 assert_correct(interior_loc, obj, file, line);
297
298 ShenandoahHeap* heap = ShenandoahHeap::heap();
299 if (!heap->marking_context()->is_marked(obj)) {
300 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
301 "Object should be marked",
302 file, line);
303 }
304 }
305
306 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
307 assert_correct(interior_loc, obj, file, line);
308
309 ShenandoahHeap* heap = ShenandoahHeap::heap();
310 if (!heap->in_collection_set(obj)) {
311 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
312 "Object should be in collection set",
313 file, line);
314 }
315 }
316
317 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
318 assert_correct(interior_loc, obj, file, line);
319
320 ShenandoahHeap* heap = ShenandoahHeap::heap();
321 if (heap->in_collection_set(obj)) {
322 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
323 "Object should not be in collection set",
324 file, line);
325 }
326 }
327
328 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
329 ShenandoahHeap* heap = ShenandoahHeap::heap();
330 if (heap->in_collection_set_loc(interior_loc)) {
331 print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
332 "Interior location should not be in collection set",
333 file, line);
334 }
335 }
336
337 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
338 const char *file, int line) {
339 ShenandoahMessageBuffer msg("%s\n", label);
340 msg.append(" Actual: " PTR_FORMAT "\n", p2i(actual));
341 report_vm_error(file, line, msg.buffer());
342 }
343
344 void ShenandoahAsserts::assert_rp_isalive_not_installed(const char *file, int line) {
345 ShenandoahHeap* heap = ShenandoahHeap::heap();
346 ReferenceProcessor* rp = heap->ref_processor();
347 if (rp->is_alive_non_header() != NULL) {
348 print_rp_failure("Shenandoah assert_rp_isalive_not_installed failed", rp->is_alive_non_header(),
349 file, line);
350 }
351 }
352
353 void ShenandoahAsserts::assert_rp_isalive_installed(const char *file, int line) {
354 ShenandoahHeap* heap = ShenandoahHeap::heap();
355 ReferenceProcessor* rp = heap->ref_processor();
356 if (rp->is_alive_non_header() == NULL) {
357 print_rp_failure("Shenandoah assert_rp_isalive_installed failed", rp->is_alive_non_header(),
358 file, line);
359 }
360 }
361
362 void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(const Monitor* lock, const char* file, int line) {
363 if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
364 return;
365 }
366
367 if (lock->owned_by_self()) {
368 return;
369 }
370
371 ShenandoahMessageBuffer msg("Must ba at a Shenandoah safepoint or held %s lock", lock->name());
372 report_vm_error(file, line, msg.buffer());
373 }
374
375 void ShenandoahAsserts::assert_heaplocked(const char* file, int line) {
376 ShenandoahHeap* heap = ShenandoahHeap::heap();
377
378 if (heap->lock()->owned_by_self()) {
379 return;
380 }
381
382 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread");
383 report_vm_error(file, line, msg.buffer());
384 }
385
386 void ShenandoahAsserts::assert_not_heaplocked(const char* file, int line) {
387 ShenandoahHeap* heap = ShenandoahHeap::heap();
388
389 if (!heap->lock()->owned_by_self()) {
390 return;
391 }
392
393 ShenandoahMessageBuffer msg("Heap lock must not be owned by current thread");
394 report_vm_error(file, line, msg.buffer());
395 }
396
397 void ShenandoahAsserts::assert_heaplocked_or_safepoint(const char* file, int line) {
398 ShenandoahHeap* heap = ShenandoahHeap::heap();
399
400 if (heap->lock()->owned_by_self()) {
401 return;
402 }
403
404 if (ShenandoahSafepoint::is_at_shenandoah_safepoint() && Thread::current()->is_VM_thread()) {
405 return;
406 }
407
408 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread, or be at safepoint");
409 report_vm_error(file, line, msg.buffer());
410 }