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 != NULL && 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.as_string());
 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.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(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 = 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, NULL, "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 != NULL && !heap->is_in(obj)) {
184     print_failure(_safe_unknown, obj, interior_loc, NULL, "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, NULL, "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 == NULL) {
203     print_failure(_safe_unknown, obj, interior_loc, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, "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, NULL, interior_loc, NULL, "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 }
--- EOF ---