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/shenandoahTraversalGC.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(loc)) return;
41
42 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
43 if (r != NULL && 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.as_string());
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((HeapWord *) obj) ? "" : "not");
70 msg.append(" %3s marked \n", ctx->is_marked(obj) ? "" : "not");
71 msg.append(" %3s in collection set\n", heap->in_collection_set(obj) ? "" : "not");
72 if (heap->traversal_gc() != NULL) {
73 msg.append(" %3s in traversal set\n", heap->traversal_gc()->traversal_set()->is_in((HeapWord*) obj) ? "" : "not");
74 }
75 msg.append(" mark:%s\n", mw_ss.as_string());
76 msg.append(" region: %s", ss.as_string());
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) ? "" : "not");
88 msg.append(" region: %s", ss.as_string());
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.as_string());
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 != NULL) {
103 stringStream ss;
104 r->print_on(&ss);
105 msg.append(" region: %s", ss.as_string());
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 != NULL && 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 != NULL) {
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 = (oop) 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 = (oop) ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
159 oop fwd2 = (oop) 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_no_check();
172
173 if (!heap->is_in(obj)) {
174 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap failed",
175 "oop must point to a heap address",
176 file, line);
177 }
178 }
179
180 void ShenandoahAsserts::assert_correct(void* interior_loc, oop obj, const char* file, int line) {
181 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
182
183 // Step 1. Check that obj is correct.
184 // After this step, it is safe to call heap_region_containing().
185 if (!heap->is_in(obj)) {
186 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
187 "oop must point to a heap address",
188 file, line);
189 }
190
191 Klass* obj_klass = obj->klass_or_null();
192 if (obj_klass == NULL) {
193 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
194 "Object klass pointer should not be NULL",
195 file,line);
196 }
197
198 if (!Metaspace::contains(obj_klass)) {
199 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
200 "Object klass pointer must go to metaspace",
201 file,line);
202 }
203
204 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
205
206 if (obj != fwd) {
207 // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
208 // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
209 // that still points to the object itself.
210 if (heap->is_full_gc_move_in_progress()) {
211 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
212 "Non-trivial forwarding pointer during Full GC moves, probable bug.",
213 file, line);
214 }
215
216 // Step 2. Check that forwardee is correct
217 if (!heap->is_in(fwd)) {
218 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
219 "Forwardee must point to a heap address",
220 file, line);
221 }
222
223 if (obj_klass != fwd->klass()) {
224 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
225 "Forwardee klass disagrees with object class",
226 file, line);
227 }
228
229 // Step 3. Check that forwardee points to correct region
230 if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
231 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
232 "Non-trivial forwardee should in another region",
233 file, line);
234 }
235
236 // Step 4. Check for multiple forwardings
237 /*
238 Disable for now. JVMTI heap walking creates 'forwarded' pattern outside cset
239 oop fwd2 = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(fwd));
240 if (fwd != fwd2) {
241 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
242 "Multiple forwardings",
243 file, line);
244 }
245 */
246 }
247 }
248
249 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
250 assert_correct(interior_loc, obj, file, line);
251
252 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
253 ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
254 if (!r->is_active()) {
255 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
256 "Object must reside in active region",
257 file, line);
258 }
259
260 size_t alloc_size = obj->size();
261 if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
262 size_t idx = r->region_number();
263 size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
264 for (size_t i = idx; i < idx + num_regions; i++) {
265 ShenandoahHeapRegion* chain_reg = heap->get_region(i);
266 if (i == idx && !chain_reg->is_humongous_start()) {
267 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
268 "Object must reside in humongous start",
269 file, line);
270 }
271 if (i != idx && !chain_reg->is_humongous_continuation()) {
272 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
273 "Humongous continuation should be of proper size",
274 file, line);
275 }
276 }
277 }
278 }
279
280 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
281 assert_correct(interior_loc, obj, file, line);
282 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
283
284 if (obj == fwd) {
285 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
286 "Object should be forwarded",
287 file, line);
288 }
289 }
290
291 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
292 assert_correct(interior_loc, obj, file, line);
293 oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
294
295 if (obj != fwd) {
296 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
297 "Object should not be forwarded",
298 file, line);
299 }
300 }
301
302 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
303 assert_correct(interior_loc, obj, file, line);
304
305 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
306 if (!heap->marking_context()->is_marked(obj)) {
307 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
308 "Object should be marked",
309 file, line);
310 }
311 }
312
313 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
314 assert_correct(interior_loc, obj, file, line);
315
316 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
317 if (!heap->in_collection_set(obj)) {
318 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
319 "Object should be in collection set",
320 file, line);
321 }
322 }
323
324 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
325 assert_correct(interior_loc, obj, file, line);
326
327 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
328 if (heap->in_collection_set(obj)) {
329 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
330 "Object should not be in collection set",
331 file, line);
332 }
333 }
334
335 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
336 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
337 if (heap->in_collection_set(interior_loc)) {
338 print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
339 "Interior location should not be in collection set",
340 file, line);
341 }
342 }
343
344 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
345 const char *file, int line) {
346 ShenandoahMessageBuffer msg("%s\n", label);
347 msg.append(" Actual: " PTR_FORMAT "\n", p2i(actual));
348 report_vm_error(file, line, msg.buffer());
349 }
350
351 void ShenandoahAsserts::assert_rp_isalive_not_installed(const char *file, int line) {
352 ShenandoahHeap* heap = ShenandoahHeap::heap();
353 ReferenceProcessor* rp = heap->ref_processor();
354 if (rp->is_alive_non_header() != NULL) {
355 print_rp_failure("Shenandoah assert_rp_isalive_not_installed failed", rp->is_alive_non_header(),
356 file, line);
357 }
358 }
359
360 void ShenandoahAsserts::assert_rp_isalive_installed(const char *file, int line) {
361 ShenandoahHeap* heap = ShenandoahHeap::heap();
362 ReferenceProcessor* rp = heap->ref_processor();
363 if (rp->is_alive_non_header() == NULL) {
364 print_rp_failure("Shenandoah assert_rp_isalive_installed failed", rp->is_alive_non_header(),
365 file, line);
366 }
367 }
368
369 void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(Mutex* lock, const char* file, int line) {
370 if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
371 return;
372 }
373
374 if (lock->owned_by_self()) {
375 return;
376 }
377
378 ShenandoahMessageBuffer msg("Must ba at a Shenandoah safepoint or held %s lock", lock->name());
379 report_vm_error(file, line, msg.buffer());
380 }
381
382 #ifdef ASSERT
383 bool ShenandoahAsserts::can_verify_oop(oop obj) {
384 if (CompressedOops::is_null(obj)) return true;
385 ShenandoahHeap* const heap = ShenandoahHeap::heap_no_check();
386 if (heap->in_collection_set(obj)) return true;
387 return false;
388 }
389 #endif