1 /*
2 * Copyright (c) 2018, 2024, Oracle and/or its affiliates. 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 #include "cds/archiveHeapLoader.inline.hpp"
27 #include "cds/cdsConfig.hpp"
28 #include "cds/heapShared.hpp"
29 #include "cds/metaspaceShared.hpp"
30 #include "classfile/classLoaderDataShared.hpp"
31 #include "classfile/systemDictionaryShared.hpp"
32 #include "gc/shared/collectedHeap.hpp"
33 #include "logging/log.hpp"
34 #include "memory/iterator.inline.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "sanitizers/ub.hpp"
38 #include "utilities/bitMap.inline.hpp"
39 #include "utilities/copy.hpp"
40
41 #if INCLUDE_CDS_JAVA_HEAP
42
43 bool ArchiveHeapLoader::_is_mapped = false;
44 bool ArchiveHeapLoader::_is_loaded = false;
45
46 bool ArchiveHeapLoader::_narrow_oop_base_initialized = false;
47 address ArchiveHeapLoader::_narrow_oop_base;
48 int ArchiveHeapLoader::_narrow_oop_shift;
49
50 // Support for loaded heap.
51 uintptr_t ArchiveHeapLoader::_loaded_heap_bottom = 0;
52 uintptr_t ArchiveHeapLoader::_loaded_heap_top = 0;
53 uintptr_t ArchiveHeapLoader::_dumptime_base = UINTPTR_MAX;
54 uintptr_t ArchiveHeapLoader::_dumptime_top = 0;
55 intx ArchiveHeapLoader::_runtime_offset = 0;
56 bool ArchiveHeapLoader::_loading_failed = false;
57
58 // Support for mapped heap.
59 uintptr_t ArchiveHeapLoader::_mapped_heap_bottom = 0;
60 bool ArchiveHeapLoader::_mapped_heap_relocation_initialized = false;
61 ptrdiff_t ArchiveHeapLoader::_mapped_heap_delta = 0;
62
63 // Every mapped region is offset by _mapped_heap_delta from its requested address.
64 // See FileMapInfo::heap_region_requested_address().
65 ATTRIBUTE_NO_UBSAN
66 void ArchiveHeapLoader::init_mapped_heap_info(address mapped_heap_bottom, ptrdiff_t delta, int dumptime_oop_shift) {
67 assert(!_mapped_heap_relocation_initialized, "only once");
68 if (!UseCompressedOops) {
69 assert(dumptime_oop_shift == 0, "sanity");
70 }
71 assert(can_map(), "sanity");
72 init_narrow_oop_decoding(CompressedOops::base() + delta, dumptime_oop_shift);
73 _mapped_heap_bottom = (intptr_t)mapped_heap_bottom;
74 _mapped_heap_delta = delta;
75 _mapped_heap_relocation_initialized = true;
76 }
77
78 void ArchiveHeapLoader::init_narrow_oop_decoding(address base, int shift) {
79 assert(!_narrow_oop_base_initialized, "only once");
80 _narrow_oop_base_initialized = true;
81 _narrow_oop_base = base;
82 _narrow_oop_shift = shift;
83 }
84
85 void ArchiveHeapLoader::fixup_region() {
86 FileMapInfo* mapinfo = FileMapInfo::current_info();
87 if (is_mapped()) {
88 mapinfo->fixup_mapped_heap_region();
89 } else if (_loading_failed) {
90 fill_failed_loaded_heap();
91 }
92 if (is_in_use()) {
93 if (!CDSConfig::is_using_full_module_graph()) {
94 // Need to remove all the archived java.lang.Module objects from HeapShared::roots().
95 ClassLoaderDataShared::clear_archived_oops();
96 }
97 }
98 }
99
100 // ------------------ Support for Region MAPPING -----------------------------------------
101
102 // Patch all the embedded oop pointers inside an archived heap region,
103 // to be consistent with the runtime oop encoding.
104 class PatchCompressedEmbeddedPointers: public BitMapClosure {
105 narrowOop* _start;
106
107 public:
108 PatchCompressedEmbeddedPointers(narrowOop* start) : _start(start) {}
109
110 bool do_bit(size_t offset) {
111 narrowOop* p = _start + offset;
112 narrowOop v = *p;
113 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
114 oop o = ArchiveHeapLoader::decode_from_mapped_archive(v);
115 RawAccess<IS_NOT_NULL>::oop_store(p, o);
116 return true;
117 }
118 };
119
120 class PatchCompressedEmbeddedPointersQuick: public BitMapClosure {
121 narrowOop* _start;
122 uint32_t _delta;
123
124 public:
125 PatchCompressedEmbeddedPointersQuick(narrowOop* start, uint32_t delta) : _start(start), _delta(delta) {}
126
127 bool do_bit(size_t offset) {
128 narrowOop* p = _start + offset;
129 narrowOop v = *p;
130 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
131 narrowOop new_v = CompressedOops::narrow_oop_cast(CompressedOops::narrow_oop_value(v) + _delta);
132 assert(!CompressedOops::is_null(new_v), "should never relocate to narrowOop(0)");
133 #ifdef ASSERT
134 oop o1 = ArchiveHeapLoader::decode_from_mapped_archive(v);
135 oop o2 = CompressedOops::decode_not_null(new_v);
136 assert(o1 == o2, "quick delta must work");
137 #endif
138 RawAccess<IS_NOT_NULL>::oop_store(p, new_v);
139 return true;
140 }
141 };
142
143 class PatchUncompressedEmbeddedPointers: public BitMapClosure {
144 oop* _start;
145
146 public:
147 PatchUncompressedEmbeddedPointers(oop* start) : _start(start) {}
148
149 bool do_bit(size_t offset) {
150 oop* p = _start + offset;
151 intptr_t dumptime_oop = (intptr_t)((void*)*p);
152 assert(dumptime_oop != 0, "null oops should have been filtered out at dump time");
153 intptr_t runtime_oop = dumptime_oop + ArchiveHeapLoader::mapped_heap_delta();
154 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(runtime_oop));
155 return true;
156 }
157 };
158
159 void ArchiveHeapLoader::patch_compressed_embedded_pointers(BitMapView bm,
160 FileMapInfo* info,
161 MemRegion region) {
162 narrowOop dt_encoded_bottom = info->encoded_heap_region_dumptime_address();
163 narrowOop rt_encoded_bottom = CompressedOops::encode_not_null(cast_to_oop(region.start()));
164 log_info(cds)("patching heap embedded pointers: narrowOop 0x%8x -> 0x%8x",
165 (uint)dt_encoded_bottom, (uint)rt_encoded_bottom);
166
167 // Optimization: if dumptime shift is the same as runtime shift, we can perform a
168 // quick conversion from "dumptime narrowOop" -> "runtime narrowOop".
169 narrowOop* patching_start = (narrowOop*)region.start() + FileMapInfo::current_info()->heap_oopmap_start_pos();
170 if (_narrow_oop_shift == CompressedOops::shift()) {
171 uint32_t quick_delta = (uint32_t)rt_encoded_bottom - (uint32_t)dt_encoded_bottom;
172 log_info(cds)("CDS heap data relocation quick delta = 0x%x", quick_delta);
173 if (quick_delta == 0) {
174 log_info(cds)("CDS heap data relocation unnecessary, quick_delta = 0");
175 } else {
176 PatchCompressedEmbeddedPointersQuick patcher(patching_start, quick_delta);
177 bm.iterate(&patcher);
178 }
179 } else {
180 log_info(cds)("CDS heap data quick relocation not possible");
181 PatchCompressedEmbeddedPointers patcher(patching_start);
182 bm.iterate(&patcher);
183 }
184 }
185
186 // Patch all the non-null pointers that are embedded in the archived heap objects
187 // in this (mapped) region
188 void ArchiveHeapLoader::patch_embedded_pointers(FileMapInfo* info,
189 MemRegion region, address oopmap,
190 size_t oopmap_size_in_bits) {
191 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
192 if (UseCompressedOops) {
193 patch_compressed_embedded_pointers(bm, info, region);
194 } else {
195 PatchUncompressedEmbeddedPointers patcher((oop*)region.start() + FileMapInfo::current_info()->heap_oopmap_start_pos());
196 bm.iterate(&patcher);
197 }
198 }
199
200 // ------------------ Support for Region LOADING -----------------------------------------
201
202 // The CDS archive remembers each heap object by its address at dump time, but
203 // the heap object may be loaded at a different address at run time. This structure is used
204 // to translate the dump time addresses for all objects in FileMapInfo::space_at(region_index)
205 // to their runtime addresses.
206 struct LoadedArchiveHeapRegion {
207 int _region_index; // index for FileMapInfo::space_at(index)
208 size_t _region_size; // number of bytes in this region
209 uintptr_t _dumptime_base; // The dump-time (decoded) address of the first object in this region
210 intx _runtime_offset; // If an object's dump time address P is within in this region, its
211 // runtime address is P + _runtime_offset
212 uintptr_t top() {
213 return _dumptime_base + _region_size;
214 }
215 };
216
217 void ArchiveHeapLoader::init_loaded_heap_relocation(LoadedArchiveHeapRegion* loaded_region) {
218 _dumptime_base = loaded_region->_dumptime_base;
219 _dumptime_top = loaded_region->top();
220 _runtime_offset = loaded_region->_runtime_offset;
221 }
222
223 bool ArchiveHeapLoader::can_load() {
224 if (!UseCompressedOops) {
225 // Pointer relocation for uncompressed oops is unimplemented.
226 return false;
227 }
228 return Universe::heap()->can_load_archived_objects();
229 }
230
231 class ArchiveHeapLoader::PatchLoadedRegionPointers: public BitMapClosure {
232 narrowOop* _start;
233 intx _offset;
234 uintptr_t _base;
235 uintptr_t _top;
236
237 public:
238 PatchLoadedRegionPointers(narrowOop* start, LoadedArchiveHeapRegion* loaded_region)
239 : _start(start),
240 _offset(loaded_region->_runtime_offset),
241 _base(loaded_region->_dumptime_base),
242 _top(loaded_region->top()) {}
243
244 bool do_bit(size_t offset) {
245 assert(UseCompressedOops, "PatchLoadedRegionPointers for uncompressed oops is unimplemented");
246 narrowOop* p = _start + offset;
247 narrowOop v = *p;
248 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
249 uintptr_t o = cast_from_oop<uintptr_t>(ArchiveHeapLoader::decode_from_archive(v));
250 assert(_base <= o && o < _top, "must be");
251
252 o += _offset;
253 ArchiveHeapLoader::assert_in_loaded_heap(o);
254 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(o));
255 return true;
256 }
257 };
258
259 bool ArchiveHeapLoader::init_loaded_region(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region,
260 MemRegion& archive_space) {
261 size_t total_bytes = 0;
262 FileMapRegion* r = mapinfo->region_at(MetaspaceShared::hp);
263 r->assert_is_heap_region();
264 if (r->used() == 0) {
265 return false;
266 }
267
268 assert(is_aligned(r->used(), HeapWordSize), "must be");
269 total_bytes += r->used();
270 loaded_region->_region_index = MetaspaceShared::hp;
271 loaded_region->_region_size = r->used();
272 loaded_region->_dumptime_base = (uintptr_t)mapinfo->heap_region_dumptime_address();
273
274 assert(is_aligned(total_bytes, HeapWordSize), "must be");
275 size_t word_size = total_bytes / HeapWordSize;
276 HeapWord* buffer = Universe::heap()->allocate_loaded_archive_space(word_size);
277 if (buffer == nullptr) {
278 return false;
279 }
280
281 archive_space = MemRegion(buffer, word_size);
282 _loaded_heap_bottom = (uintptr_t)archive_space.start();
283 _loaded_heap_top = _loaded_heap_bottom + total_bytes;
284
285 loaded_region->_runtime_offset = _loaded_heap_bottom - loaded_region->_dumptime_base;
286
287 return true;
288 }
289
290 bool ArchiveHeapLoader::load_heap_region_impl(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region,
291 uintptr_t load_address) {
292 uintptr_t bitmap_base = (uintptr_t)mapinfo->map_bitmap_region();
293 if (bitmap_base == 0) {
294 _loading_failed = true;
295 return false; // OOM or CRC error
296 }
297
298 FileMapRegion* r = mapinfo->region_at(loaded_region->_region_index);
299 if (!mapinfo->read_region(loaded_region->_region_index, (char*)load_address, r->used(), /* do_commit = */ false)) {
300 // There's no easy way to free the buffer, so we will fill it with zero later
301 // in fill_failed_loaded_heap(), and it will eventually be GC'ed.
302 log_warning(cds)("Loading of heap region %d has failed. Archived objects are disabled", loaded_region->_region_index);
303 _loading_failed = true;
304 return false;
305 }
306 assert(r->mapped_base() == (char*)load_address, "sanity");
307 log_info(cds)("Loaded heap region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT
308 " size " SIZE_FORMAT_W(6) " delta " INTX_FORMAT,
309 loaded_region->_region_index, load_address, load_address + loaded_region->_region_size,
310 loaded_region->_region_size, loaded_region->_runtime_offset);
311
312 uintptr_t oopmap = bitmap_base + r->oopmap_offset();
313 BitMapView bm((BitMap::bm_word_t*)oopmap, r->oopmap_size_in_bits());
314
315 PatchLoadedRegionPointers patcher((narrowOop*)load_address + FileMapInfo::current_info()->heap_oopmap_start_pos(), loaded_region);
316 bm.iterate(&patcher);
317 return true;
318 }
319
320 bool ArchiveHeapLoader::load_heap_region(FileMapInfo* mapinfo) {
321 assert(UseCompressedOops, "loaded heap for !UseCompressedOops is unimplemented");
322 init_narrow_oop_decoding(mapinfo->narrow_oop_base(), mapinfo->narrow_oop_shift());
323
324 LoadedArchiveHeapRegion loaded_region;
325 memset(&loaded_region, 0, sizeof(loaded_region));
326
327 MemRegion archive_space;
328 if (!init_loaded_region(mapinfo, &loaded_region, archive_space)) {
329 return false;
330 }
331
332 if (!load_heap_region_impl(mapinfo, &loaded_region, (uintptr_t)archive_space.start())) {
333 assert(_loading_failed, "must be");
334 return false;
335 }
336
337 init_loaded_heap_relocation(&loaded_region);
338 _is_loaded = true;
339
340 return true;
341 }
342
343 class VerifyLoadedHeapEmbeddedPointers: public BasicOopIterateClosure {
344 ResourceHashtable<uintptr_t, bool>* _table;
345
346 public:
347 VerifyLoadedHeapEmbeddedPointers(ResourceHashtable<uintptr_t, bool>* table) : _table(table) {}
348
349 virtual void do_oop(narrowOop* p) {
350 // This should be called before the loaded region is modified, so all the embedded pointers
351 // must be null, or must point to a valid object in the loaded region.
352 narrowOop v = *p;
353 if (!CompressedOops::is_null(v)) {
354 oop o = CompressedOops::decode_not_null(v);
355 uintptr_t u = cast_from_oop<uintptr_t>(o);
356 ArchiveHeapLoader::assert_in_loaded_heap(u);
357 guarantee(_table->contains(u), "must point to beginning of object in loaded archived region");
358 }
359 }
360 virtual void do_oop(oop* p) {
361 // Uncompressed oops are not supported by loaded heaps.
362 Unimplemented();
363 }
364 };
365
366 void ArchiveHeapLoader::finish_initialization() {
367 if (is_loaded()) {
368 // These operations are needed only when the heap is loaded (not mapped).
369 finish_loaded_heap();
370 if (VerifyArchivedFields > 0) {
371 verify_loaded_heap();
372 }
373 }
374 if (is_in_use()) {
375 patch_native_pointers();
376 intptr_t bottom = is_loaded() ? _loaded_heap_bottom : _mapped_heap_bottom;
377
378 // The heap roots are stored in one or more segments that are laid out consecutively.
379 // The size of each segment (except for the last one) is max_size_in_{elems,bytes}.
380 HeapRootSegments segments = FileMapInfo::current_info()->heap_root_segments();
381 HeapShared::init_root_segment_sizes(segments.max_size_in_elems());
382 intptr_t first_segment_addr = bottom + segments.base_offset();
383 for (size_t c = 0; c < segments.count(); c++) {
384 oop segment_oop = cast_to_oop(first_segment_addr + (c * segments.max_size_in_bytes()));
385 assert(segment_oop->is_objArray(), "Must be");
386 HeapShared::add_root_segment((objArrayOop)segment_oop);
387 }
388 }
389 }
390
391 void ArchiveHeapLoader::finish_loaded_heap() {
392 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
393 HeapWord* top = (HeapWord*)_loaded_heap_top;
394
395 MemRegion archive_space = MemRegion(bottom, top);
396 Universe::heap()->complete_loaded_archive_space(archive_space);
397 }
398
399 void ArchiveHeapLoader::verify_loaded_heap() {
400 log_info(cds, heap)("Verify all oops and pointers in loaded heap");
401
402 ResourceMark rm;
403 ResourceHashtable<uintptr_t, bool> table;
404 VerifyLoadedHeapEmbeddedPointers verifier(&table);
405 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
406 HeapWord* top = (HeapWord*)_loaded_heap_top;
407
408 for (HeapWord* p = bottom; p < top; ) {
409 oop o = cast_to_oop(p);
410 table.put(cast_from_oop<uintptr_t>(o), true);
411 p += o->size();
412 }
413
414 for (HeapWord* p = bottom; p < top; ) {
415 oop o = cast_to_oop(p);
416 o->oop_iterate(&verifier);
417 p += o->size();
418 }
419 }
420
421 void ArchiveHeapLoader::fill_failed_loaded_heap() {
422 assert(_loading_failed, "must be");
423 if (_loaded_heap_bottom != 0) {
424 assert(_loaded_heap_top != 0, "must be");
425 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
426 HeapWord* top = (HeapWord*)_loaded_heap_top;
427 Universe::heap()->fill_with_objects(bottom, top - bottom);
428 }
429 }
430
431 class PatchNativePointers: public BitMapClosure {
432 Metadata** _start;
433
434 public:
435 PatchNativePointers(Metadata** start) : _start(start) {}
436
437 bool do_bit(size_t offset) {
438 Metadata** p = _start + offset;
439 *p = (Metadata*)(address(*p) + MetaspaceShared::relocation_delta());
440 // Currently we have only Klass pointers in heap objects.
441 // This needs to be relaxed when we support other types of native
442 // pointers such as Method.
443 assert(((Klass*)(*p))->is_klass(), "must be");
444 return true;
445 }
446 };
447
448 void ArchiveHeapLoader::patch_native_pointers() {
449 if (MetaspaceShared::relocation_delta() == 0) {
450 return;
451 }
452
453 FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::hp);
454 if (r->mapped_base() != nullptr && r->has_ptrmap()) {
455 log_info(cds, heap)("Patching native pointers in heap region");
456 BitMapView bm = FileMapInfo::current_info()->ptrmap_view(MetaspaceShared::hp);
457 PatchNativePointers patcher((Metadata**)r->mapped_base() + FileMapInfo::current_info()->heap_ptrmap_start_pos());
458 bm.iterate(&patcher);
459 }
460 }
461 #endif // INCLUDE_CDS_JAVA_HEAP