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 "classfile/vmClasses.hpp"
33 #include "gc/shared/collectedHeap.hpp"
34 #include "logging/log.hpp"
35 #include "memory/iterator.inline.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "memory/universe.hpp"
38 #include "sanitizers/ub.hpp"
39 #include "utilities/bitMap.inline.hpp"
40 #include "utilities/copy.hpp"
41
42 #if INCLUDE_CDS_JAVA_HEAP
43
44 bool ArchiveHeapLoader::_is_mapped = false;
45 bool ArchiveHeapLoader::_is_loaded = false;
46
47 bool ArchiveHeapLoader::_narrow_oop_base_initialized = false;
48 address ArchiveHeapLoader::_narrow_oop_base;
49 int ArchiveHeapLoader::_narrow_oop_shift;
50
51 // Support for loaded heap.
52 uintptr_t ArchiveHeapLoader::_loaded_heap_bottom = 0;
53 uintptr_t ArchiveHeapLoader::_loaded_heap_top = 0;
54 uintptr_t ArchiveHeapLoader::_dumptime_base = UINTPTR_MAX;
55 uintptr_t ArchiveHeapLoader::_dumptime_top = 0;
56 intx ArchiveHeapLoader::_runtime_offset = 0;
57 bool ArchiveHeapLoader::_loading_failed = false;
58
59 // Support for mapped heap.
60 uintptr_t ArchiveHeapLoader::_mapped_heap_bottom = 0;
61 bool ArchiveHeapLoader::_mapped_heap_relocation_initialized = false;
62 ptrdiff_t ArchiveHeapLoader::_mapped_heap_delta = 0;
63
64 // Every mapped region is offset by _mapped_heap_delta from its requested address.
65 // See FileMapInfo::heap_region_requested_address().
66 ATTRIBUTE_NO_UBSAN
67 void ArchiveHeapLoader::init_mapped_heap_info(address mapped_heap_bottom, ptrdiff_t delta, int dumptime_oop_shift) {
68 assert(!_mapped_heap_relocation_initialized, "only once");
69 if (!UseCompressedOops) {
70 assert(dumptime_oop_shift == 0, "sanity");
71 }
72 assert(can_map(), "sanity");
73 init_narrow_oop_decoding(CompressedOops::base() + delta, dumptime_oop_shift);
74 _mapped_heap_bottom = (intptr_t)mapped_heap_bottom;
75 _mapped_heap_delta = delta;
76 _mapped_heap_relocation_initialized = true;
77 }
78
79 void ArchiveHeapLoader::init_narrow_oop_decoding(address base, int shift) {
80 assert(!_narrow_oop_base_initialized, "only once");
81 _narrow_oop_base_initialized = true;
82 _narrow_oop_base = base;
83 _narrow_oop_shift = shift;
84 }
85
86 void ArchiveHeapLoader::fixup_region() {
87 FileMapInfo* mapinfo = FileMapInfo::current_info();
88 if (is_mapped()) {
89 mapinfo->fixup_mapped_heap_region();
90 } else if (_loading_failed) {
91 fill_failed_loaded_heap();
92 }
93 if (is_in_use()) {
94 if (!CDSConfig::is_using_full_module_graph()) {
95 // Need to remove all the archived java.lang.Module objects from HeapShared::roots().
96 ClassLoaderDataShared::clear_archived_oops();
97 }
98 }
99 }
100
101 // ------------------ Support for Region MAPPING -----------------------------------------
102
103 // Patch all the embedded oop pointers inside an archived heap region,
104 // to be consistent with the runtime oop encoding.
105 class PatchCompressedEmbeddedPointers: public BitMapClosure {
106 narrowOop* _start;
107
108 public:
109 PatchCompressedEmbeddedPointers(narrowOop* start) : _start(start) {}
110
111 bool do_bit(size_t offset) {
112 narrowOop* p = _start + offset;
113 narrowOop v = *p;
114 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
115 oop o = ArchiveHeapLoader::decode_from_mapped_archive(v);
116 RawAccess<IS_NOT_NULL>::oop_store(p, o);
117 return true;
118 }
119 };
120
121 class PatchCompressedEmbeddedPointersQuick: public BitMapClosure {
122 narrowOop* _start;
123 uint32_t _delta;
124
125 public:
126 PatchCompressedEmbeddedPointersQuick(narrowOop* start, uint32_t delta) : _start(start), _delta(delta) {}
127
128 bool do_bit(size_t offset) {
129 narrowOop* p = _start + offset;
130 narrowOop v = *p;
131 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
132 narrowOop new_v = CompressedOops::narrow_oop_cast(CompressedOops::narrow_oop_value(v) + _delta);
133 assert(!CompressedOops::is_null(new_v), "should never relocate to narrowOop(0)");
134 #ifdef ASSERT
135 oop o1 = ArchiveHeapLoader::decode_from_mapped_archive(v);
136 oop o2 = CompressedOops::decode_not_null(new_v);
137 assert(o1 == o2, "quick delta must work");
138 #endif
139 RawAccess<IS_NOT_NULL>::oop_store(p, new_v);
140 return true;
141 }
142 };
143
144 class PatchUncompressedEmbeddedPointers: public BitMapClosure {
145 oop* _start;
146
147 public:
148 PatchUncompressedEmbeddedPointers(oop* start) : _start(start) {}
149
150 bool do_bit(size_t offset) {
151 oop* p = _start + offset;
152 intptr_t dumptime_oop = (intptr_t)((void*)*p);
153 assert(dumptime_oop != 0, "null oops should have been filtered out at dump time");
154 intptr_t runtime_oop = dumptime_oop + ArchiveHeapLoader::mapped_heap_delta();
155 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(runtime_oop));
156 return true;
157 }
158 };
159
160 void ArchiveHeapLoader::patch_compressed_embedded_pointers(BitMapView bm,
161 FileMapInfo* info,
162 MemRegion region) {
163 narrowOop dt_encoded_bottom = info->encoded_heap_region_dumptime_address();
164 narrowOop rt_encoded_bottom = CompressedOops::encode_not_null(cast_to_oop(region.start()));
165 log_info(cds)("patching heap embedded pointers: narrowOop 0x%8x -> 0x%8x",
166 (uint)dt_encoded_bottom, (uint)rt_encoded_bottom);
167
168 // Optimization: if dumptime shift is the same as runtime shift, we can perform a
169 // quick conversion from "dumptime narrowOop" -> "runtime narrowOop".
170 narrowOop* patching_start = (narrowOop*)region.start() + FileMapInfo::current_info()->heap_oopmap_start_pos();
171 if (_narrow_oop_shift == CompressedOops::shift()) {
172 uint32_t quick_delta = (uint32_t)rt_encoded_bottom - (uint32_t)dt_encoded_bottom;
173 log_info(cds)("CDS heap data relocation quick delta = 0x%x", quick_delta);
174 if (quick_delta == 0) {
175 log_info(cds)("CDS heap data relocation unnecessary, quick_delta = 0");
176 } else {
177 PatchCompressedEmbeddedPointersQuick patcher(patching_start, quick_delta);
178 bm.iterate(&patcher);
179 }
180 } else {
181 log_info(cds)("CDS heap data quick relocation not possible");
182 PatchCompressedEmbeddedPointers patcher(patching_start);
183 bm.iterate(&patcher);
184 }
185 }
186
187 // Patch all the non-null pointers that are embedded in the archived heap objects
188 // in this (mapped) region
189 void ArchiveHeapLoader::patch_embedded_pointers(FileMapInfo* info,
190 MemRegion region, address oopmap,
191 size_t oopmap_size_in_bits) {
192 BitMapView bm((BitMap::bm_word_t*)oopmap, oopmap_size_in_bits);
193 if (UseCompressedOops) {
194 patch_compressed_embedded_pointers(bm, info, region);
195 } else {
196 PatchUncompressedEmbeddedPointers patcher((oop*)region.start() + FileMapInfo::current_info()->heap_oopmap_start_pos());
197 bm.iterate(&patcher);
198 }
199 }
200
201 // ------------------ Support for Region LOADING -----------------------------------------
202
203 // The CDS archive remembers each heap object by its address at dump time, but
204 // the heap object may be loaded at a different address at run time. This structure is used
205 // to translate the dump time addresses for all objects in FileMapInfo::space_at(region_index)
206 // to their runtime addresses.
207 struct LoadedArchiveHeapRegion {
208 int _region_index; // index for FileMapInfo::space_at(index)
209 size_t _region_size; // number of bytes in this region
210 uintptr_t _dumptime_base; // The dump-time (decoded) address of the first object in this region
211 intx _runtime_offset; // If an object's dump time address P is within in this region, its
212 // runtime address is P + _runtime_offset
213 uintptr_t top() {
214 return _dumptime_base + _region_size;
215 }
216 };
217
218 void ArchiveHeapLoader::init_loaded_heap_relocation(LoadedArchiveHeapRegion* loaded_region) {
219 _dumptime_base = loaded_region->_dumptime_base;
220 _dumptime_top = loaded_region->top();
221 _runtime_offset = loaded_region->_runtime_offset;
222 }
223
224 bool ArchiveHeapLoader::can_load() {
225 if (!UseCompressedOops) {
226 // Pointer relocation for uncompressed oops is unimplemented.
227 return false;
228 }
229 return Universe::heap()->can_load_archived_objects();
230 }
231
232 class ArchiveHeapLoader::PatchLoadedRegionPointers: public BitMapClosure {
233 narrowOop* _start;
234 intx _offset;
235 uintptr_t _base;
236 uintptr_t _top;
237
238 public:
239 PatchLoadedRegionPointers(narrowOop* start, LoadedArchiveHeapRegion* loaded_region)
240 : _start(start),
241 _offset(loaded_region->_runtime_offset),
242 _base(loaded_region->_dumptime_base),
243 _top(loaded_region->top()) {}
244
245 bool do_bit(size_t offset) {
246 assert(UseCompressedOops, "PatchLoadedRegionPointers for uncompressed oops is unimplemented");
247 narrowOop* p = _start + offset;
248 narrowOop v = *p;
249 assert(!CompressedOops::is_null(v), "null oops should have been filtered out at dump time");
250 uintptr_t o = cast_from_oop<uintptr_t>(ArchiveHeapLoader::decode_from_archive(v));
251 assert(_base <= o && o < _top, "must be");
252
253 o += _offset;
254 ArchiveHeapLoader::assert_in_loaded_heap(o);
255 RawAccess<IS_NOT_NULL>::oop_store(p, cast_to_oop(o));
256 return true;
257 }
258 };
259
260 bool ArchiveHeapLoader::init_loaded_region(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region,
261 MemRegion& archive_space) {
262 size_t total_bytes = 0;
263 FileMapRegion* r = mapinfo->region_at(MetaspaceShared::hp);
264 r->assert_is_heap_region();
265 if (r->used() == 0) {
266 return false;
267 }
268
269 assert(is_aligned(r->used(), HeapWordSize), "must be");
270 total_bytes += r->used();
271 loaded_region->_region_index = MetaspaceShared::hp;
272 loaded_region->_region_size = r->used();
273 loaded_region->_dumptime_base = (uintptr_t)mapinfo->heap_region_dumptime_address();
274
275 assert(is_aligned(total_bytes, HeapWordSize), "must be");
276 size_t word_size = total_bytes / HeapWordSize;
277 HeapWord* buffer = Universe::heap()->allocate_loaded_archive_space(word_size);
278 if (buffer == nullptr) {
279 return false;
280 }
281
282 archive_space = MemRegion(buffer, word_size);
283 _loaded_heap_bottom = (uintptr_t)archive_space.start();
284 _loaded_heap_top = _loaded_heap_bottom + total_bytes;
285
286 loaded_region->_runtime_offset = _loaded_heap_bottom - loaded_region->_dumptime_base;
287
288 return true;
289 }
290
291 bool ArchiveHeapLoader::load_heap_region_impl(FileMapInfo* mapinfo, LoadedArchiveHeapRegion* loaded_region,
292 uintptr_t load_address) {
293 uintptr_t bitmap_base = (uintptr_t)mapinfo->map_bitmap_region();
294 if (bitmap_base == 0) {
295 _loading_failed = true;
296 return false; // OOM or CRC error
297 }
298
299 FileMapRegion* r = mapinfo->region_at(loaded_region->_region_index);
300 if (!mapinfo->read_region(loaded_region->_region_index, (char*)load_address, r->used(), /* do_commit = */ false)) {
301 // There's no easy way to free the buffer, so we will fill it with zero later
302 // in fill_failed_loaded_heap(), and it will eventually be GC'ed.
303 log_warning(cds)("Loading of heap region %d has failed. Archived objects are disabled", loaded_region->_region_index);
304 _loading_failed = true;
305 return false;
306 }
307 assert(r->mapped_base() == (char*)load_address, "sanity");
308 log_info(cds)("Loaded heap region #%d at base " INTPTR_FORMAT " top " INTPTR_FORMAT
309 " size " SIZE_FORMAT_W(6) " delta " INTX_FORMAT,
310 loaded_region->_region_index, load_address, load_address + loaded_region->_region_size,
311 loaded_region->_region_size, loaded_region->_runtime_offset);
312
313 uintptr_t oopmap = bitmap_base + r->oopmap_offset();
314 BitMapView bm((BitMap::bm_word_t*)oopmap, r->oopmap_size_in_bits());
315
316 PatchLoadedRegionPointers patcher((narrowOop*)load_address + FileMapInfo::current_info()->heap_oopmap_start_pos(), loaded_region);
317 bm.iterate(&patcher);
318 return true;
319 }
320
321 bool ArchiveHeapLoader::load_heap_region(FileMapInfo* mapinfo) {
322 assert(UseCompressedOops, "loaded heap for !UseCompressedOops is unimplemented");
323 init_narrow_oop_decoding(mapinfo->narrow_oop_base(), mapinfo->narrow_oop_shift());
324
325 LoadedArchiveHeapRegion loaded_region;
326 memset(&loaded_region, 0, sizeof(loaded_region));
327
328 MemRegion archive_space;
329 if (!init_loaded_region(mapinfo, &loaded_region, archive_space)) {
330 return false;
331 }
332
333 if (!load_heap_region_impl(mapinfo, &loaded_region, (uintptr_t)archive_space.start())) {
334 assert(_loading_failed, "must be");
335 return false;
336 }
337
338 init_loaded_heap_relocation(&loaded_region);
339 _is_loaded = true;
340
341 return true;
342 }
343
344 class VerifyLoadedHeapEmbeddedPointers: public BasicOopIterateClosure {
345 ResourceHashtable<uintptr_t, bool>* _table;
346
347 public:
348 VerifyLoadedHeapEmbeddedPointers(ResourceHashtable<uintptr_t, bool>* table) : _table(table) {}
349
350 virtual void do_oop(narrowOop* p) {
351 // This should be called before the loaded region is modified, so all the embedded pointers
352 // must be null, or must point to a valid object in the loaded region.
353 narrowOop v = *p;
354 if (!CompressedOops::is_null(v)) {
355 oop o = CompressedOops::decode_not_null(v);
356 uintptr_t u = cast_from_oop<uintptr_t>(o);
357 ArchiveHeapLoader::assert_in_loaded_heap(u);
358 guarantee(_table->contains(u), "must point to beginning of object in loaded archived region");
359 }
360 }
361 virtual void do_oop(oop* p) {
362 // Uncompressed oops are not supported by loaded heaps.
363 Unimplemented();
364 }
365 };
366
367 void ArchiveHeapLoader::finish_initialization() {
368 if (is_loaded()) {
369 // These operations are needed only when the heap is loaded (not mapped).
370 finish_loaded_heap();
371 if (VerifyArchivedFields > 0) {
372 verify_loaded_heap();
373 }
374 }
375 if (is_in_use()) {
376 patch_native_pointers();
377 intptr_t bottom = is_loaded() ? _loaded_heap_bottom : _mapped_heap_bottom;
378
379 // The heap roots are stored in one or more segments that are laid out consecutively.
380 // The size of each segment (except for the last one) is max_size_in_{elems,bytes}.
381 HeapRootSegments segments = FileMapInfo::current_info()->heap_root_segments();
382 HeapShared::init_root_segment_sizes(segments.max_size_in_elems());
383 intptr_t first_segment_addr = bottom + segments.base_offset();
384 for (size_t c = 0; c < segments.count(); c++) {
385 oop segment_oop = cast_to_oop(first_segment_addr + (c * segments.max_size_in_bytes()));
386 assert(segment_oop->is_objArray(), "Must be");
387 HeapShared::add_root_segment((objArrayOop)segment_oop);
388 }
389 }
390 }
391
392 void ArchiveHeapLoader::finish_loaded_heap() {
393 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
394 HeapWord* top = (HeapWord*)_loaded_heap_top;
395
396 MemRegion archive_space = MemRegion(bottom, top);
397 Universe::heap()->complete_loaded_archive_space(archive_space);
398 }
399
400 void ArchiveHeapLoader::verify_loaded_heap() {
401 log_info(cds, heap)("Verify all oops and pointers in loaded heap");
402
403 ResourceMark rm;
404 ResourceHashtable<uintptr_t, bool> table;
405 VerifyLoadedHeapEmbeddedPointers verifier(&table);
406 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
407 HeapWord* top = (HeapWord*)_loaded_heap_top;
408
409 for (HeapWord* p = bottom; p < top; ) {
410 oop o = cast_to_oop(p);
411 table.put(cast_from_oop<uintptr_t>(o), true);
412 p += o->size();
413 }
414
415 for (HeapWord* p = bottom; p < top; ) {
416 oop o = cast_to_oop(p);
417 o->oop_iterate(&verifier);
418 p += o->size();
419 }
420 }
421
422 void ArchiveHeapLoader::fill_failed_loaded_heap() {
423 assert(_loading_failed, "must be");
424 if (_loaded_heap_bottom != 0) {
425 assert(_loaded_heap_top != 0, "must be");
426 HeapWord* bottom = (HeapWord*)_loaded_heap_bottom;
427 HeapWord* top = (HeapWord*)_loaded_heap_top;
428 Universe::heap()->fill_with_objects(bottom, top - bottom);
429 }
430 }
431
432 oop ArchiveHeapLoader::oop_from_offset(int offset) {
433 // Once GC starts, the offsets saved in CachedCodeDirectoryInternal::_permanent_oop_offsets
434 // will become invalid. I don't know what function can check if GCs are allowed, but surely
435 // GCs can't happen before the Object class is loaded.
436 assert(CDSConfig::is_using_archive(), "sanity");
437 assert(vmClasses::Object_klass()->class_loader_data() == nullptr,
438 "can be called only very early during VM start-up");
439 if (is_loaded()) {
440 return cast_to_oop(_loaded_heap_bottom + offset);
441 } else {
442 assert(is_mapped(), "must be");
443 return cast_to_oop(_mapped_heap_bottom + offset);
444 }
445 }
446
447 class PatchNativePointers: public BitMapClosure {
448 Metadata** _start;
449
450 public:
451 PatchNativePointers(Metadata** start) : _start(start) {}
452
453 bool do_bit(size_t offset) {
454 Metadata** p = _start + offset;
455 *p = (Metadata*)(address(*p) + MetaspaceShared::relocation_delta());
456 return true;
457 }
458 };
459
460 void ArchiveHeapLoader::patch_native_pointers() {
461 if (MetaspaceShared::relocation_delta() == 0) {
462 return;
463 }
464
465 FileMapRegion* r = FileMapInfo::current_info()->region_at(MetaspaceShared::hp);
466 if (r->mapped_base() != nullptr && r->has_ptrmap()) {
467 log_info(cds, heap)("Patching native pointers in heap region");
468 BitMapView bm = FileMapInfo::current_info()->ptrmap_view(MetaspaceShared::hp);
469 PatchNativePointers patcher((Metadata**)r->mapped_base() + FileMapInfo::current_info()->heap_ptrmap_start_pos());
470 bm.iterate(&patcher);
471 }
472 }
473 #endif // INCLUDE_CDS_JAVA_HEAP