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 (!oopDesc::equals_raw(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 (!oopDesc::equals_raw(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 (!oopDesc::equals_raw(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     oop fwd2 = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(fwd));
 238     if (!oopDesc::equals_raw(fwd, fwd2)) {
 239       print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
 240                     "Multiple forwardings",
 241                     file, line);
 242     }
 243   }
 244 }
 245 
 246 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
 247   assert_correct(interior_loc, obj, file, line);
 248 
 249   ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
 250   ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
 251   if (!r->is_active()) {
 252     print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
 253                   "Object must reside in active region",
 254                   file, line);
 255   }
 256 
 257   size_t alloc_size = obj->size();
 258   if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
 259     size_t idx = r->region_number();
 260     size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
 261     for (size_t i = idx; i < idx + num_regions; i++) {
 262       ShenandoahHeapRegion* chain_reg = heap->get_region(i);
 263       if (i == idx && !chain_reg->is_humongous_start()) {
 264         print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
 265                       "Object must reside in humongous start",
 266                       file, line);
 267       }
 268       if (i != idx && !chain_reg->is_humongous_continuation()) {
 269         print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
 270                       "Humongous continuation should be of proper size",
 271                       file, line);
 272       }
 273     }
 274   }
 275 }
 276 
 277 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
 278   assert_correct(interior_loc, obj, file, line);
 279   oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
 280 
 281   if (oopDesc::equals_raw(obj, fwd)) {
 282     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
 283                   "Object should be forwarded",
 284                   file, line);
 285   }
 286 }
 287 
 288 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
 289   assert_correct(interior_loc, obj, file, line);
 290   oop fwd = oop(ShenandoahForwarding::get_forwardee_raw_unchecked(obj));
 291 
 292   if (!oopDesc::equals_raw(obj, fwd)) {
 293     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
 294                   "Object should not be forwarded",
 295                   file, line);
 296   }
 297 }
 298 
 299 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
 300   assert_correct(interior_loc, obj, file, line);
 301 
 302   ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
 303   if (!heap->marking_context()->is_marked(obj)) {
 304     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
 305                   "Object should be marked",
 306                   file, line);
 307   }
 308 }
 309 
 310 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
 311   assert_correct(interior_loc, obj, file, line);
 312 
 313   ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
 314   if (!heap->in_collection_set(obj)) {
 315     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
 316                   "Object should be in collection set",
 317                   file, line);
 318   }
 319 }
 320 
 321 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
 322   assert_correct(interior_loc, obj, file, line);
 323 
 324   ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
 325   if (heap->in_collection_set(obj)) {
 326     print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
 327                   "Object should not be in collection set",
 328                   file, line);
 329   }
 330 }
 331 
 332 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
 333   ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
 334   if (heap->in_collection_set(interior_loc)) {
 335     print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
 336                   "Interior location should not be in collection set",
 337                   file, line);
 338   }
 339 }
 340 
 341 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
 342                                          const char *file, int line) {
 343   ShenandoahMessageBuffer msg("%s\n", label);
 344   msg.append(" Actual:                  " PTR_FORMAT "\n", p2i(actual));
 345   report_vm_error(file, line, msg.buffer());
 346 }
 347 
 348 void ShenandoahAsserts::assert_rp_isalive_not_installed(const char *file, int line) {
 349   ShenandoahHeap* heap = ShenandoahHeap::heap();
 350   ReferenceProcessor* rp = heap->ref_processor();
 351   if (rp->is_alive_non_header() != NULL) {
 352     print_rp_failure("Shenandoah assert_rp_isalive_not_installed failed", rp->is_alive_non_header(),
 353                      file, line);
 354   }
 355 }
 356 
 357 void ShenandoahAsserts::assert_rp_isalive_installed(const char *file, int line) {
 358   ShenandoahHeap* heap = ShenandoahHeap::heap();
 359   ReferenceProcessor* rp = heap->ref_processor();
 360   if (rp->is_alive_non_header() == NULL) {
 361     print_rp_failure("Shenandoah assert_rp_isalive_installed failed", rp->is_alive_non_header(),
 362                      file, line);
 363   }
 364 }