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_reserved(loc)) return; 41 42 ShenandoahHeapRegion* r = heap->heap_region_containing(loc); 43 if (r != nullptr && 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.freeze()); 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.freeze()); 75 msg.append(" region: %s", ss.freeze()); 76 } 77 78 void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) { 79 ShenandoahHeap* heap = ShenandoahHeap::heap(); 80 if (heap->is_in_reserved(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.freeze()); 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.freeze()); 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_reserved(loc)) { 100 ShenandoahHeapRegion* r = heap->heap_region_containing(loc); 101 if (r != nullptr) { 102 stringStream ss; 103 r->print_on(&ss); 104 msg.append(" region: %s", ss.freeze()); 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 != nullptr && heap->is_in_reserved(loc)); 117 118 ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label); 119 120 msg.append("Referenced from:\n"); 121 if (interior_loc != nullptr) { 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_bounds(void* interior_loc, oop obj, const char *file, int line) { 170 ShenandoahHeap* heap = ShenandoahHeap::heap(); 171 172 if (!heap->is_in_reserved(obj)) { 173 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_heap_bounds failed", 174 "oop must be in heap bounds", 175 file, line); 176 } 177 } 178 179 void ShenandoahAsserts::assert_in_heap_bounds_or_null(void* interior_loc, oop obj, const char *file, int line) { 180 ShenandoahHeap* heap = ShenandoahHeap::heap(); 181 182 if (obj != nullptr && !heap->is_in_reserved(obj)) { 183 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_heap_bounds_or_null failed", 184 "oop must be in heap bounds", 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_reserved(obj)) { 195 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 196 "oop must be in heap bounds", 197 file, line); 198 } 199 200 Klass* obj_klass = obj->klass_or_null(); 201 if (obj_klass == nullptr) { 202 print_failure(_safe_unknown, obj, interior_loc, nullptr, "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, nullptr, "Shenandoah assert_correct failed", 209 "Object klass pointer must go to metaspace", 210 file,line); 211 } 212 213 if (!heap->is_in(obj)) { 214 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 215 "Object should be in active region area", 216 file, line); 217 } 218 219 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); 220 221 if (obj != fwd) { 222 // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something 223 // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr 224 // that still points to the object itself. 225 if (heap->is_full_gc_move_in_progress()) { 226 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 227 "Non-trivial forwarding pointer during Full GC moves, probable bug.", 228 file, line); 229 } 230 231 // Step 2. Check that forwardee is correct 232 if (!heap->is_in_reserved(fwd)) { 233 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 234 "Forwardee must be in heap bounds", 235 file, line); 236 } 237 238 if (obj_klass != fwd->klass()) { 239 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 240 "Forwardee klass disagrees with object class", 241 file, line); 242 } 243 244 // Step 3. Check that forwardee points to correct region 245 if (!heap->is_in(fwd)) { 246 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 247 "Forwardee should be in active region area", 248 file, line); 249 } 250 251 if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) { 252 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 253 "Non-trivial forwardee should be in another region", 254 file, line); 255 } 256 257 // Step 4. Check for multiple forwardings 258 oop fwd2 = ShenandoahForwarding::get_forwardee_raw_unchecked(fwd); 259 if (fwd != fwd2) { 260 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 261 "Multiple forwardings", 262 file, line); 263 } 264 } 265 266 // Do additional checks for special objects: their fields can hold metadata as well. 267 // We want to check class loading/unloading did not corrupt them. 268 269 if (Universe::is_fully_initialized() && (obj_klass == vmClasses::Class_klass())) { 270 Metadata* klass = obj->metadata_field(java_lang_Class::klass_offset()); 271 if (klass != nullptr && !Metaspace::contains(klass)) { 272 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 273 "Instance class mirror should point to Metaspace", 274 file, line); 275 } 276 277 Metadata* array_klass = obj->metadata_field(java_lang_Class::array_klass_offset()); 278 if (array_klass != nullptr && !Metaspace::contains(array_klass)) { 279 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_correct failed", 280 "Array class mirror should point to Metaspace", 281 file, line); 282 } 283 } 284 } 285 286 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) { 287 assert_correct(interior_loc, obj, file, line); 288 289 ShenandoahHeap* heap = ShenandoahHeap::heap(); 290 ShenandoahHeapRegion* r = heap->heap_region_containing(obj); 291 if (!r->is_active()) { 292 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed", 293 "Object must reside in active region", 294 file, line); 295 } 296 297 size_t alloc_size = obj->size(); 298 HeapWord* obj_end = cast_from_oop<HeapWord*>(obj) + alloc_size; 299 300 if (ShenandoahHeapRegion::requires_humongous(alloc_size)) { 301 size_t idx = r->index(); 302 size_t end_idx = heap->heap_region_index_containing(obj_end - 1); 303 for (size_t i = idx; i < end_idx; i++) { 304 ShenandoahHeapRegion* chain_reg = heap->get_region(i); 305 if (i == idx && !chain_reg->is_humongous_start()) { 306 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed", 307 "Object must reside in humongous start", 308 file, line); 309 } 310 if (i != idx && !chain_reg->is_humongous_continuation()) { 311 print_failure(_safe_oop, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed", 312 "Humongous continuation should be of proper size", 313 file, line); 314 } 315 } 316 } else { 317 if (obj_end > r->top()) { 318 print_failure(_safe_unknown, obj, interior_loc, nullptr, "Shenandoah assert_in_correct_region failed", 319 "Object end should be within the active area of the region", 320 file, line); 321 } 322 } 323 } 324 325 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) { 326 assert_correct(interior_loc, obj, file, line); 327 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); 328 329 if (obj == fwd) { 330 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_forwarded failed", 331 "Object should be forwarded", 332 file, line); 333 } 334 } 335 336 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) { 337 assert_correct(interior_loc, obj, file, line); 338 oop fwd = ShenandoahForwarding::get_forwardee_raw_unchecked(obj); 339 340 if (obj != fwd) { 341 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_not_forwarded failed", 342 "Object should not be forwarded", 343 file, line); 344 } 345 } 346 347 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) { 348 assert_correct(interior_loc, obj, file, line); 349 350 ShenandoahHeap* heap = ShenandoahHeap::heap(); 351 if (!heap->marking_context()->is_marked(obj)) { 352 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked failed", 353 "Object should be marked", 354 file, line); 355 } 356 } 357 358 void ShenandoahAsserts::assert_marked_weak(void *interior_loc, oop obj, const char *file, int line) { 359 assert_correct(interior_loc, obj, file, line); 360 361 ShenandoahHeap* heap = ShenandoahHeap::heap(); 362 if (!heap->marking_context()->is_marked_weak(obj)) { 363 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked_weak failed", 364 "Object should be marked weakly", 365 file, line); 366 } 367 } 368 369 void ShenandoahAsserts::assert_marked_strong(void *interior_loc, oop obj, const char *file, int line) { 370 assert_correct(interior_loc, obj, file, line); 371 372 ShenandoahHeap* heap = ShenandoahHeap::heap(); 373 if (!heap->marking_context()->is_marked_strong(obj)) { 374 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_marked_strong failed", 375 "Object should be marked strongly", 376 file, line); 377 } 378 } 379 380 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) { 381 assert_correct(interior_loc, obj, file, line); 382 383 ShenandoahHeap* heap = ShenandoahHeap::heap(); 384 if (!heap->in_collection_set(obj)) { 385 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_in_cset failed", 386 "Object should be in collection set", 387 file, line); 388 } 389 } 390 391 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) { 392 assert_correct(interior_loc, obj, file, line); 393 394 ShenandoahHeap* heap = ShenandoahHeap::heap(); 395 if (heap->in_collection_set(obj)) { 396 print_failure(_safe_all, obj, interior_loc, nullptr, "Shenandoah assert_not_in_cset failed", 397 "Object should not be in collection set", 398 file, line); 399 } 400 } 401 402 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) { 403 ShenandoahHeap* heap = ShenandoahHeap::heap(); 404 if (heap->in_collection_set_loc(interior_loc)) { 405 print_failure(_safe_unknown, nullptr, interior_loc, nullptr, "Shenandoah assert_not_in_cset_loc failed", 406 "Interior location should not be in collection set", 407 file, line); 408 } 409 } 410 411 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual, 412 const char *file, int line) { 413 ShenandoahMessageBuffer msg("%s\n", label); 414 msg.append(" Actual: " PTR_FORMAT "\n", p2i(actual)); 415 report_vm_error(file, line, msg.buffer()); 416 } 417 418 void ShenandoahAsserts::assert_locked_or_shenandoah_safepoint(Mutex* lock, const char* file, int line) { 419 if (ShenandoahSafepoint::is_at_shenandoah_safepoint()) { 420 return; 421 } 422 423 if (lock->owned_by_self()) { 424 return; 425 } 426 427 ShenandoahMessageBuffer msg("Must ba at a Shenandoah safepoint or held %s lock", lock->name()); 428 report_vm_error(file, line, msg.buffer()); 429 } 430 431 void ShenandoahAsserts::assert_heaplocked(const char* file, int line) { 432 ShenandoahHeap* heap = ShenandoahHeap::heap(); 433 434 if (heap->lock()->owned_by_self()) { 435 return; 436 } 437 438 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread"); 439 report_vm_error(file, line, msg.buffer()); 440 } 441 442 void ShenandoahAsserts::assert_not_heaplocked(const char* file, int line) { 443 ShenandoahHeap* heap = ShenandoahHeap::heap(); 444 445 if (!heap->lock()->owned_by_self()) { 446 return; 447 } 448 449 ShenandoahMessageBuffer msg("Heap lock must not be owned by current thread"); 450 report_vm_error(file, line, msg.buffer()); 451 } 452 453 void ShenandoahAsserts::assert_heaplocked_or_safepoint(const char* file, int line) { 454 ShenandoahHeap* heap = ShenandoahHeap::heap(); 455 456 if (heap->lock()->owned_by_self()) { 457 return; 458 } 459 460 if (ShenandoahSafepoint::is_at_shenandoah_safepoint() && Thread::current()->is_VM_thread()) { 461 return; 462 } 463 464 ShenandoahMessageBuffer msg("Heap lock must be owned by current thread, or be at safepoint"); 465 report_vm_error(file, line, msg.buffer()); 466 }