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(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(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.as_string());
 75   msg.append("  region: %s", ss.as_string());
 76 }
 77 
 78 void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) {
 79   ShenandoahHeap* heap = ShenandoahHeap::heap();
 80   if (heap->is_in(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.as_string());
 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.as_string());
 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(loc)) {
100     ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
101     if (r != NULL) {
102       stringStream ss;
103       r->print_on(&ss);
104       msg.append("  region: %s", ss.as_string());
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 != NULL && heap->is_in(loc));
117 
118   ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label);
119 
120   msg.append("Referenced from:\n");
121   if (interior_loc != NULL) {
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(void* interior_loc, oop obj, const char *file, int line) {
170   ShenandoahHeap* heap = ShenandoahHeap::heap();
171 
172   if (!heap->is_in(obj)) {
173     print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap failed",
174                   "oop must point to a heap address",
175                   file, line);
176   }
177 }
178 
179 void ShenandoahAsserts::assert_in_heap_or_null(void* interior_loc, oop obj, const char *file, int line) {
180   ShenandoahHeap* heap = ShenandoahHeap::heap();
181 
182   if (obj != NULL && !heap->is_in(obj)) {
183     print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap_or_null failed",
184                   "oop must point to a heap address",
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(obj)) {
195     print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
196                   "oop must point to a heap address",
197                   file, line);
198   }
199 
200   Klass* obj_klass = obj->klass_or_null();
201   if (obj_klass == NULL) {
202     print_failure(_safe_unknown, obj, interior_loc, NULL, "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, NULL, "Shenandoah assert_correct failed",
209                   "Object klass pointer must go to metaspace",
210                   file,line);
211   }
212 
213   oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
214 
215   if (obj != fwd) {
216     // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
217     // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
218     // that still points to the object itself.
219     if (heap->is_full_gc_move_in_progress()) {
220       print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
221                     "Non-trivial forwarding pointer during Full GC moves, probable bug.",
222                     file, line);
223     }
224 
225     // Step 2. Check that forwardee is correct
226     if (!heap->is_in(fwd)) {
227       print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
228                     "Forwardee must point to a heap address",
229                     file, line);
230     }
231 
232     if (obj_klass != fwd->klass()) {
233       print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
234                     "Forwardee klass disagrees with object class",
235                     file, line);
236     }
237 
238     // Step 3. Check that forwardee points to correct region
239     if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
240       print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
241                     "Non-trivial forwardee should in another region",
242                     file, line);
243     }
244 
245     // Step 4. Check for multiple forwardings
246     oop fwd2 = ShenandoahForwarding::get_forwardee_raw_unchecked(fwd);
247     if (fwd != fwd2) {
248       print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
249                     "Multiple forwardings",
250                     file, line);
251     }
252   }
253 }
254 
255 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
256   assert_correct(interior_loc, obj, file, line);
257 
258   ShenandoahHeap* heap = ShenandoahHeap::heap();
259   ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
260   if (!r->is_active()) {
261     print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
262                   "Object must reside in active region",
263                   file, line);
264   }
265 
266   size_t alloc_size = obj->size();
267   if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
268     size_t idx = r->index();
269     size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
270     for (size_t i = idx; i < idx + num_regions; i++) {
271       ShenandoahHeapRegion* chain_reg = heap->get_region(i);
272       if (i == idx && !chain_reg->is_humongous_start()) {
273         print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
274                       "Object must reside in humongous start",
275                       file, line);
276       }
277       if (i != idx && !chain_reg->is_humongous_continuation()) {
278         print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
279                       "Humongous continuation should be of proper size",
280                       file, line);
281       }
282     }
283   }
284 }
285 
286 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
287   assert_correct(interior_loc, obj, file, line);
288   oop fwd =   ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
289 
290   if (obj == fwd) {
291     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
292                   "Object should be forwarded",
293                   file, line);
294   }
295 }
296 
297 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
298   assert_correct(interior_loc, obj, file, line);
299   oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj);
300 
301   if (obj != fwd) {
302     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
303                   "Object should not be forwarded",
304                   file, line);
305   }
306 }
307 
308 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
309   assert_correct(interior_loc, obj, file, line);
310 
311   ShenandoahHeap* heap = ShenandoahHeap::heap();
312   if (!heap->marking_context()->is_marked(obj)) {
313     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
314                   "Object should be marked",
315                   file, line);
316   }
317 }
318 
319 void ShenandoahAsserts::assert_marked_weak(void *interior_loc, oop obj, const char *file, int line) {
320   assert_correct(interior_loc, obj, file, line);
321 
322   ShenandoahHeap* heap = ShenandoahHeap::heap();
323   if (!heap->marking_context()->is_marked_weak(obj)) {
324     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked_weak failed",
325                   "Object should be marked weakly",
326                   file, line);
327   }
328 }
329 
330 void ShenandoahAsserts::assert_marked_strong(void *interior_loc, oop obj, const char *file, int line) {
331   assert_correct(interior_loc, obj, file, line);
332 
333   ShenandoahHeap* heap = ShenandoahHeap::heap();
334   if (!heap->marking_context()->is_marked_strong(obj)) {
335     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked_strong failed",
336                   "Object should be marked strongly",
337                   file, line);
338   }
339 }
340 
341 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
342   assert_correct(interior_loc, obj, file, line);
343 
344   ShenandoahHeap* heap = ShenandoahHeap::heap();
345   if (!heap->in_collection_set(obj)) {
346     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
347                   "Object should be in collection set",
348                   file, line);
349   }
350 }
351 
352 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
353   assert_correct(interior_loc, obj, file, line);
354 
355   ShenandoahHeap* heap = ShenandoahHeap::heap();
356   if (heap->in_collection_set(obj)) {
357     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
358                   "Object should not be in collection set",
359                   file, line);
360   }
361 }
362 
363 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
364   ShenandoahHeap* heap = ShenandoahHeap::heap();
365   if (heap->in_collection_set_loc(interior_loc)) {
366     print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
367                   "Interior location should not be in collection set",
368                   file, line);
369   }
370 }
371 
372 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
373                                          const char *file, int line) {
374   ShenandoahMessageBuffer msg("%s\n", label);
375   msg.append(" Actual:                  " PTR_FORMAT "\n", p2i(actual));
376   report_vm_error(file, line, msg.buffer());
377 }
378 
379 void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(Mutex* lock, const char* file, int line) {
380   if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) {
381     return;
382   }
383 
384   if (lock->owned_by_self()) {
385     return;
386   }
387 
388   ShenandoahMessageBuffer msg("Must ba at a Shenandoah safepoint or held %s lock", lock->name());
389   report_vm_error(file, line, msg.buffer());
390 }
391 
392 void ShenandoahAsserts::assert_heaplocked(const char* file, int line) {
393   ShenandoahHeap* heap = ShenandoahHeap::heap();
394 
395   if (heap->lock()->owned_by_self()) {
396     return;
397   }
398 
399   ShenandoahMessageBuffer msg("Heap lock must be owned by current thread");
400   report_vm_error(file, line, msg.buffer());
401 }
402 
403 void ShenandoahAsserts::assert_not_heaplocked(const char* file, int line) {
404   ShenandoahHeap* heap = ShenandoahHeap::heap();
405 
406   if (!heap->lock()->owned_by_self()) {
407     return;
408   }
409 
410   ShenandoahMessageBuffer msg("Heap lock must not be owned by current thread");
411   report_vm_error(file, line, msg.buffer());
412 }
413 
414 void ShenandoahAsserts::assert_heaplocked_or_safepoint(const char* file, int line) {
415   ShenandoahHeap* heap = ShenandoahHeap::heap();
416 
417   if (heap->lock()->owned_by_self()) {
418     return;
419   }
420 
421   if (ShenandoahSafepoint::is_at_shenandoah_safepoint() && Thread::current()->is_VM_thread()) {
422     return;
423   }
424 
425   ShenandoahMessageBuffer msg("Heap lock must be owned by current thread, or be at safepoint");
426   report_vm_error(file, line, msg.buffer());
427 }
--- EOF ---