1 /*
2 * Copyright (c) 1997, 2025, 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 "code/codeCache.hpp"
26 #include "code/compiledIC.hpp"
27 #include "code/nmethod.hpp"
28 #include "code/relocInfo.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "memory/universe.hpp"
31 #include "oops/compressedOops.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "runtime/flags/flagSetting.hpp"
34 #include "runtime/stubCodeGenerator.hpp"
35 #include "utilities/align.hpp"
36 #include "utilities/checkedCast.hpp"
37 #include "utilities/copy.hpp"
38
39 #include <new>
40 #include <type_traits>
41
42 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
43
44
45 // Implementation of relocInfo
46
47 #ifdef ASSERT
48 relocInfo::relocType relocInfo::check_relocType(relocType type) {
49 assert(type != data_prefix_tag, "cannot build a prefix this way");
50 assert((type & type_mask) == type, "wrong type");
51 return type;
52 }
53
54 void relocInfo::check_offset_and_format(int offset, int format) {
55 assert(offset >= 0 && offset < offset_limit(), "offset out off bounds");
56 assert(is_aligned(offset, offset_unit), "misaligned offset");
57 assert((format & format_mask) == format, "wrong format");
58 }
59 #endif // ASSERT
60
61 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
62 relocInfo* data = this+1; // here's where the data might go
63 dest->set_locs_end(data); // sync end: the next call may read dest.locs_end
64 reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
65 relocInfo* data_limit = dest->locs_end();
66 if (data_limit > data) {
67 relocInfo suffix = (*this);
68 data_limit = this->finish_prefix((short*) data_limit);
69 // Finish up with the suffix. (Hack note: pack_data_to might edit this.)
70 *data_limit = suffix;
71 dest->set_locs_end(data_limit+1);
72 }
73 }
74
75 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
76 assert(sizeof(relocInfo) == sizeof(short), "change this code");
77 short* p = (short*)(this+1);
78 assert(prefix_limit >= p, "must be a valid span of data");
79 int plen = checked_cast<int>(prefix_limit - p);
80 if (plen == 0) {
81 debug_only(_value = 0xFFFF);
82 return this; // no data: remove self completely
83 }
84 if (plen == 1 && fits_into_immediate(p[0])) {
85 (*this) = immediate_relocInfo(p[0]); // move data inside self
86 return this+1;
87 }
88 // cannot compact, so just update the count and return the limit pointer
89 (*this) = prefix_info(plen); // write new datalen
90 assert(data() + datalen() == prefix_limit, "pointers must line up");
91 return (relocInfo*)prefix_limit;
92 }
93
94 void relocInfo::set_type(relocType t) {
95 int old_offset = addr_offset();
96 int old_format = format();
97 (*this) = relocInfo(t, old_offset, old_format);
98 assert(type()==(int)t, "sanity check");
99 assert(addr_offset()==old_offset, "sanity check");
100 assert(format()==old_format, "sanity check");
101 }
102
103 void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
104 bool found = false;
105 while (itr->next() && !found) {
106 if (itr->addr() == pc) {
107 assert(itr->type()==old_type, "wrong relocInfo type found");
108 itr->current()->set_type(new_type);
109 found=true;
110 }
111 }
112 assert(found, "no relocInfo found for pc");
113 }
114
115
116 // ----------------------------------------------------------------------------------------------------
117 // Implementation of RelocIterator
118
119 // A static dummy to serve as a safe pointer when there is no relocation info.
120 static relocInfo dummy_relocInfo = relocInfo(relocInfo::none, 0);
121
122 void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
123 initialize_misc();
124
125 if (nm == nullptr && begin != nullptr) {
126 // allow nmethod to be deduced from beginning address
127 CodeBlob* cb = CodeCache::find_blob(begin);
128 nm = (cb != nullptr) ? cb->as_nmethod_or_null() : nullptr;
129 }
130 guarantee(nm != nullptr, "must be able to deduce nmethod from other arguments");
131
132 _code = nm;
133 if (nm->relocation_size() == 0) {
134 _current = &dummy_relocInfo - 1;
135 _end = &dummy_relocInfo;
136 } else {
137 assert(((nm->relocation_begin() != nullptr) && (nm->relocation_end() != nullptr)), "valid start and end pointer");
138 _current = nm->relocation_begin() - 1;
139 _end = nm->relocation_end();
140 }
141 _addr = nm->content_begin();
142
143 // Initialize code sections.
144 _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
145 _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
146 _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin() ;
147
148 _section_end [CodeBuffer::SECT_CONSTS] = nm->consts_end() ;
149 _section_end [CodeBuffer::SECT_INSTS ] = nm->insts_end() ;
150 _section_end [CodeBuffer::SECT_STUBS ] = nm->stub_end() ;
151
152 assert(!has_current(), "just checking");
153 assert(begin == nullptr || begin >= nm->code_begin(), "in bounds");
154 assert(limit == nullptr || limit <= nm->code_end(), "in bounds");
155 set_limits(begin, limit);
156 }
157
158
159 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
160 initialize_misc();
161 assert(((cs->locs_start() != nullptr) && (cs->locs_end() != nullptr)), "valid start and end pointer");
162 _current = cs->locs_start() - 1;
163 _end = cs->locs_end();
164 _addr = cs->start();
165 _code = nullptr; // Not cb->blob();
166
167 CodeBuffer* cb = cs->outer();
168 assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
169 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
170 CodeSection* cs = cb->code_section(n);
171 _section_start[n] = cs->start();
172 _section_end [n] = cs->end();
173 }
174
175 assert(!has_current(), "just checking");
176
177 assert(begin == nullptr || begin >= cs->start(), "in bounds");
178 assert(limit == nullptr || limit <= cs->end(), "in bounds");
179 set_limits(begin, limit);
180 }
181
182 bool RelocIterator::addr_in_const() const {
183 const int n = CodeBuffer::SECT_CONSTS;
184 return section_start(n) <= addr() && addr() < section_end(n);
185 }
186
187
188 void RelocIterator::set_limits(address begin, address limit) {
189 _limit = limit;
190
191 // the limit affects this next stuff:
192 if (begin != nullptr) {
193 relocInfo* backup;
194 address backup_addr;
195 while (true) {
196 backup = _current;
197 backup_addr = _addr;
198 if (!next() || addr() >= begin) break;
199 }
200 // At this point, either we are at the first matching record,
201 // or else there is no such record, and !has_current().
202 // In either case, revert to the immediately preceding state.
203 _current = backup;
204 _addr = backup_addr;
205 set_has_current(false);
206 }
207 }
208
209
210 // All the strange bit-encodings are in here.
211 // The idea is to encode relocation data which are small integers
212 // very efficiently (a single extra halfword). Larger chunks of
213 // relocation data need a halfword header to hold their size.
214 void RelocIterator::advance_over_prefix() {
215 if (_current->is_datalen()) {
216 _data = (short*) _current->data();
217 _datalen = _current->datalen();
218 _current += _datalen + 1; // skip the embedded data & header
219 } else {
220 _databuf = _current->immediate();
221 _data = &_databuf;
222 _datalen = 1;
223 _current++; // skip the header
224 }
225 // The client will see the following relocInfo, whatever that is.
226 // It is the reloc to which the preceding data applies.
227 }
228
229
230 void RelocIterator::initialize_misc() {
231 set_has_current(false);
232 for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
233 _section_start[i] = nullptr; // these will be lazily computed, if needed
234 _section_end [i] = nullptr;
235 }
236 }
237
238
239 Relocation* RelocIterator::reloc() {
240 // (take the "switch" out-of-line)
241 relocInfo::relocType t = type();
242 if (false) {}
243 #define EACH_TYPE(name) \
244 else if (t == relocInfo::name##_type) { \
245 return name##_reloc(); \
246 }
247 APPLY_TO_RELOCATIONS(EACH_TYPE);
248 #undef EACH_TYPE
249 assert(t == relocInfo::none, "must be padding");
250 _rh = RelocationHolder::none;
251 return _rh.reloc();
252 }
253
254 // Verify all the destructors are trivial, so we don't need to worry about
255 // destroying old contents of a RelocationHolder being assigned or destroyed.
256 #define VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Reloc) \
257 static_assert(std::is_trivially_destructible<Reloc>::value, "must be");
258
259 #define VERIFY_TRIVIALLY_DESTRUCTIBLE(name) \
260 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(PASTE_TOKENS(name, _Relocation));
261
262 APPLY_TO_RELOCATIONS(VERIFY_TRIVIALLY_DESTRUCTIBLE)
263 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Relocation)
264
265 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX
266 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE
267
268 // Define all the copy_into functions. These rely on all Relocation types
269 // being trivially destructible (verified above). So it doesn't matter
270 // whether the target holder has been previously initialized or not. There's
271 // no need to consider that distinction and destruct the relocation in an
272 // already initialized holder.
273 #define DEFINE_COPY_INTO_AUX(Reloc) \
274 void Reloc::copy_into(RelocationHolder& holder) const { \
275 copy_into_helper(*this, holder); \
276 }
277
278 #define DEFINE_COPY_INTO(name) \
279 DEFINE_COPY_INTO_AUX(PASTE_TOKENS(name, _Relocation))
280
281 APPLY_TO_RELOCATIONS(DEFINE_COPY_INTO)
282 DEFINE_COPY_INTO_AUX(Relocation)
283
284 #undef DEFINE_COPY_INTO_AUX
285 #undef DEFINE_COPY_INTO
286
287 //////// Methods for flyweight Relocation types
288
289 // some relocations can compute their own values
290 address Relocation::value() {
291 ShouldNotReachHere();
292 return nullptr;
293 }
294
295
296 void Relocation::set_value(address x) {
297 ShouldNotReachHere();
298 }
299
300 void Relocation::const_set_data_value(address x) {
301 #ifdef _LP64
302 if (format() == relocInfo::narrow_oop_in_const) {
303 *(narrowOop*)addr() = CompressedOops::encode(cast_to_oop(x));
304 } else {
305 #endif
306 *(address*)addr() = x;
307 #ifdef _LP64
308 }
309 #endif
310 }
311
312 void Relocation::const_verify_data_value(address x) {
313 #ifdef _LP64
314 if (format() == relocInfo::narrow_oop_in_const) {
315 guarantee(*(narrowOop*)addr() == CompressedOops::encode(cast_to_oop(x)), "must agree");
316 } else {
317 #endif
318 guarantee(*(address*)addr() == x, "must agree");
319 #ifdef _LP64
320 }
321 #endif
322 }
323
324
325 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
326 if (rtype == relocInfo::none) return RelocationHolder::none;
327 relocInfo ri = relocInfo(rtype, 0);
328 RelocIterator itr;
329 itr.set_current(ri);
330 itr.reloc();
331 return itr._rh;
332 }
333
334 address Relocation::old_addr_for(address newa,
335 const CodeBuffer* src, CodeBuffer* dest) {
336 int sect = dest->section_index_of(newa);
337 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
338 address ostart = src->code_section(sect)->start();
339 address nstart = dest->code_section(sect)->start();
340 return ostart + (newa - nstart);
341 }
342
343 address Relocation::new_addr_for(address olda,
344 const CodeBuffer* src, CodeBuffer* dest) {
345 debug_only(const CodeBuffer* src0 = src);
346 int sect = CodeBuffer::SECT_NONE;
347 // Look for olda in the source buffer, and all previous incarnations
348 // if the source buffer has been expanded.
349 for (; src != nullptr; src = src->before_expand()) {
350 sect = src->section_index_of(olda);
351 if (sect != CodeBuffer::SECT_NONE) break;
352 }
353 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
354 address ostart = src->code_section(sect)->start();
355 address nstart = dest->code_section(sect)->start();
356 return nstart + (olda - ostart);
357 }
358
359 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
360 address addr0 = addr;
361 if (addr0 == nullptr || dest->allocates2(addr0)) return;
362 CodeBuffer* cb = dest->outer();
363 addr = new_addr_for(addr0, cb, cb);
364 assert(allow_other_sections || dest->contains2(addr),
365 "addr must be in required section");
366 }
367
368
369 void CallRelocation::set_destination(address x) {
370 pd_set_call_destination(x);
371 }
372
373 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
374 // Usually a self-relative reference to an external routine.
375 // On some platforms, the reference is absolute (not self-relative).
376 // The enhanced use of pd_call_destination sorts this all out.
377 address orig_addr = old_addr_for(addr(), src, dest);
378 address callee = pd_call_destination(orig_addr);
379 // Reassert the callee address, this time in the new copy of the code.
380 pd_set_call_destination(callee);
381 }
382
383
384 #ifdef USE_TRAMPOLINE_STUB_FIX_OWNER
385 void trampoline_stub_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
386 // Finalize owner destination only for nmethods
387 if (dest->blob() != nullptr) return;
388 pd_fix_owner_after_move();
389 }
390 #endif
391
392 //// pack/unpack methods
393
394 void oop_Relocation::pack_data_to(CodeSection* dest) {
395 short* p = (short*) dest->locs_end();
396 p = pack_1_int_to(p, _oop_index);
397 dest->set_locs_end((relocInfo*) p);
398 }
399
400
401 void oop_Relocation::unpack_data() {
402 _oop_index = unpack_1_int();
403 }
404
405 void metadata_Relocation::pack_data_to(CodeSection* dest) {
406 short* p = (short*) dest->locs_end();
407 p = pack_1_int_to(p, _metadata_index);
408 dest->set_locs_end((relocInfo*) p);
409 }
410
411
412 void metadata_Relocation::unpack_data() {
413 _metadata_index = unpack_1_int();
414 }
415
416
417 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
418 short* p = (short*) dest->locs_end();
419 address point = dest->locs_point();
420
421 normalize_address(_cached_value, dest);
422 jint x0 = scaled_offset_null_special(_cached_value, point);
423 p = pack_2_ints_to(p, x0, _method_index);
424 dest->set_locs_end((relocInfo*) p);
425 }
426
427
428 void virtual_call_Relocation::unpack_data() {
429 jint x0 = 0;
430 unpack_2_ints(x0, _method_index);
431 address point = addr();
432 _cached_value = x0==0? nullptr: address_from_scaled_offset(x0, point);
433 }
434
435 void runtime_call_w_cp_Relocation::pack_data_to(CodeSection * dest) {
436 short* p = pack_1_int_to((short *)dest->locs_end(), (jint)(_offset >> 2));
437 dest->set_locs_end((relocInfo*) p);
438 }
439
440 void runtime_call_w_cp_Relocation::unpack_data() {
441 _offset = unpack_1_int() << 2;
442 }
443
444 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
445 short* p = (short*) dest->locs_end();
446 CodeSection* insts = dest->outer()->insts();
447 normalize_address(_static_call, insts);
448 p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
449 dest->set_locs_end((relocInfo*) p);
450 }
451
452 void static_stub_Relocation::unpack_data() {
453 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
454 jint offset = unpack_1_int();
455 _static_call = address_from_scaled_offset(offset, base);
456 }
457
458 void trampoline_stub_Relocation::pack_data_to(CodeSection* dest ) {
459 short* p = (short*) dest->locs_end();
460 CodeSection* insts = dest->outer()->insts();
461 normalize_address(_owner, insts);
462 p = pack_1_int_to(p, scaled_offset(_owner, insts->start()));
463 dest->set_locs_end((relocInfo*) p);
464 }
465
466 void trampoline_stub_Relocation::unpack_data() {
467 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
468 _owner = address_from_scaled_offset(unpack_1_int(), base);
469 }
470
471 void external_word_Relocation::pack_data_to(CodeSection* dest) {
472 short* p = (short*) dest->locs_end();
473 int index = ExternalsRecorder::find_index(_target);
474 p = pack_1_int_to(p, index);
475 dest->set_locs_end((relocInfo*) p);
476 }
477
478
479 void external_word_Relocation::unpack_data() {
480 int index = unpack_1_int();
481 _target = ExternalsRecorder::at(index);
482 }
483
484
485 void internal_word_Relocation::pack_data_to(CodeSection* dest) {
486 short* p = (short*) dest->locs_end();
487 normalize_address(_target, dest, true);
488
489 // Check whether my target address is valid within this section.
490 // If not, strengthen the relocation type to point to another section.
491 int sindex = _section;
492 if (sindex == CodeBuffer::SECT_NONE && _target != nullptr
493 && (!dest->allocates(_target) || _target == dest->locs_point())) {
494 sindex = dest->outer()->section_index_of(_target);
495 guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
496 relocInfo* base = dest->locs_end() - 1;
497 assert(base->type() == this->type(), "sanity");
498 // Change the written type, to be section_word_type instead.
499 base->set_type(relocInfo::section_word_type);
500 }
501
502 // Note: An internal_word relocation cannot refer to its own instruction,
503 // because we reserve "0" to mean that the pointer itself is embedded
504 // in the code stream. We use a section_word relocation for such cases.
505
506 if (sindex == CodeBuffer::SECT_NONE) {
507 assert(type() == relocInfo::internal_word_type, "must be base class");
508 guarantee(_target == nullptr || dest->allocates2(_target), "must be within the given code section");
509 jint x0 = scaled_offset_null_special(_target, dest->locs_point());
510 assert(!(x0 == 0 && _target != nullptr), "correct encoding of null target");
511 p = pack_1_int_to(p, x0);
512 } else {
513 assert(_target != nullptr, "sanity");
514 CodeSection* sect = dest->outer()->code_section(sindex);
515 guarantee(sect->allocates2(_target), "must be in correct section");
516 address base = sect->start();
517 jint offset = scaled_offset(_target, base);
518 assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
519 assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
520 p = pack_1_int_to(p, (offset << section_width) | sindex);
521 }
522
523 dest->set_locs_end((relocInfo*) p);
524 }
525
526
527 void internal_word_Relocation::unpack_data() {
528 jint x0 = unpack_1_int();
529 _target = x0==0? nullptr: address_from_scaled_offset(x0, addr());
530 _section = CodeBuffer::SECT_NONE;
531 }
532
533
534 void section_word_Relocation::unpack_data() {
535 jint x = unpack_1_int();
536 jint offset = (x >> section_width);
537 int sindex = (x & ((1<<section_width)-1));
538 address base = binding()->section_start(sindex);
539
540 _section = sindex;
541 _target = address_from_scaled_offset(offset, base);
542 }
543
544 //// miscellaneous methods
545 oop* oop_Relocation::oop_addr() {
546 int n = _oop_index;
547 if (n == 0) {
548 // oop is stored in the code stream
549 return (oop*) pd_address_in_code();
550 } else {
551 // oop is stored in table at nmethod::oops_begin
552 return code()->oop_addr_at(n);
553 }
554 }
555
556
557 oop oop_Relocation::oop_value() {
558 // clean inline caches store a special pseudo-null
559 if (Universe::contains_non_oop_word(oop_addr())) {
560 return nullptr;
561 }
562 return *oop_addr();
563 }
564
565
566 void oop_Relocation::fix_oop_relocation() {
567 if (!oop_is_immediate()) {
568 // get the oop from the pool, and re-insert it into the instruction:
569 set_value(value());
570 }
571 }
572
573
574 void oop_Relocation::verify_oop_relocation() {
575 if (!oop_is_immediate()) {
576 // get the oop from the pool, and re-insert it into the instruction:
577 verify_value(value());
578 }
579 }
580
581 // meta data versions
582 Metadata** metadata_Relocation::metadata_addr() {
583 int n = _metadata_index;
584 if (n == 0) {
585 // metadata is stored in the code stream
586 return (Metadata**) pd_address_in_code();
587 } else {
588 // metadata is stored in table at nmethod::metadatas_begin
589 return code()->metadata_addr_at(n);
590 }
591 }
592
593
594 Metadata* metadata_Relocation::metadata_value() {
595 Metadata* v = *metadata_addr();
596 // clean inline caches store a special pseudo-null
597 if (v == (Metadata*)Universe::non_oop_word()) v = nullptr;
598 return v;
599 }
600
601
602 void metadata_Relocation::fix_metadata_relocation() {
603 if (!metadata_is_immediate()) {
604 // get the metadata from the pool, and re-insert it into the instruction:
605 pd_fix_value(value());
606 }
607 }
608
609 address virtual_call_Relocation::cached_value() {
610 assert(_cached_value != nullptr && _cached_value < addr(), "must precede ic_call");
611 return _cached_value;
612 }
613
614 Method* virtual_call_Relocation::method_value() {
615 nmethod* nm = code();
616 if (nm == nullptr) return (Method*)nullptr;
617 Metadata* m = nm->metadata_at(_method_index);
618 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
619 assert(m == nullptr || m->is_method(), "not a method");
620 return (Method*)m;
621 }
622
623 void virtual_call_Relocation::clear_inline_cache() {
624 ResourceMark rm;
625 CompiledIC* icache = CompiledIC_at(this);
626 icache->set_to_clean();
627 }
628
629
630 void opt_virtual_call_Relocation::pack_data_to(CodeSection* dest) {
631 short* p = (short*) dest->locs_end();
632 p = pack_1_int_to(p, _method_index);
633 dest->set_locs_end((relocInfo*) p);
634 }
635
636 void opt_virtual_call_Relocation::unpack_data() {
637 _method_index = unpack_1_int();
638 }
639
640 Method* opt_virtual_call_Relocation::method_value() {
641 nmethod* nm = code();
642 if (nm == nullptr) return (Method*)nullptr;
643 Metadata* m = nm->metadata_at(_method_index);
644 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
645 assert(m == nullptr || m->is_method(), "not a method");
646 return (Method*)m;
647 }
648
649 void opt_virtual_call_Relocation::clear_inline_cache() {
650 ResourceMark rm;
651 CompiledDirectCall* callsite = CompiledDirectCall::at(this);
652 callsite->set_to_clean();
653 }
654
655 address opt_virtual_call_Relocation::static_stub() {
656 // search for the static stub who points back to this static call
657 address static_call_addr = addr();
658 RelocIterator iter(code());
659 while (iter.next()) {
660 if (iter.type() == relocInfo::static_stub_type) {
661 static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
662 if (stub_reloc->static_call() == static_call_addr) {
663 return iter.addr();
664 }
665 }
666 }
667 return nullptr;
668 }
669
670 Method* static_call_Relocation::method_value() {
671 nmethod* nm = code();
672 if (nm == nullptr) return (Method*)nullptr;
673 Metadata* m = nm->metadata_at(_method_index);
674 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
675 assert(m == nullptr || m->is_method(), "not a method");
676 return (Method*)m;
677 }
678
679 void static_call_Relocation::pack_data_to(CodeSection* dest) {
680 short* p = (short*) dest->locs_end();
681 p = pack_1_int_to(p, _method_index);
682 dest->set_locs_end((relocInfo*) p);
683 }
684
685 void static_call_Relocation::unpack_data() {
686 _method_index = unpack_1_int();
687 }
688
689 void static_call_Relocation::clear_inline_cache() {
690 ResourceMark rm;
691 CompiledDirectCall* callsite = CompiledDirectCall::at(this);
692 callsite->set_to_clean();
693 }
694
695
696 address static_call_Relocation::static_stub() {
697 // search for the static stub who points back to this static call
698 address static_call_addr = addr();
699 RelocIterator iter(code());
700 while (iter.next()) {
701 if (iter.type() == relocInfo::static_stub_type) {
702 static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
703 if (stub_reloc->static_call() == static_call_addr) {
704 return iter.addr();
705 }
706 }
707 }
708 return nullptr;
709 }
710
711 // Finds the trampoline address for a call. If no trampoline stub is
712 // found nullptr is returned which can be handled by the caller.
713 address trampoline_stub_Relocation::get_trampoline_for(address call, nmethod* code) {
714 // There are no relocations available when the code gets relocated
715 // because of CodeBuffer expansion.
716 if (code->relocation_size() == 0)
717 return nullptr;
718
719 RelocIterator iter(code, call);
720 while (iter.next()) {
721 if (iter.type() == relocInfo::trampoline_stub_type) {
722 if (iter.trampoline_stub_reloc()->owner() == call) {
723 return iter.addr();
724 }
725 }
726 }
727
728 return nullptr;
729 }
730
731 void static_stub_Relocation::clear_inline_cache() {
732 // Call stub is only used when calling the interpreted code.
733 // It does not really need to be cleared, except that we want to clean out the methodoop.
734 CompiledDirectCall::set_stub_to_clean(this);
735 }
736
737
738 void external_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
739 if (_target != nullptr) {
740 // Probably this reference is absolute, not relative, so the following is
741 // probably a no-op.
742 set_value(_target);
743 }
744 // If target is nullptr, this is an absolute embedded reference to an external
745 // location, which means there is nothing to fix here. In either case, the
746 // resulting target should be an "external" address.
747 postcond(src->section_index_of(target()) == CodeBuffer::SECT_NONE);
748 postcond(dest->section_index_of(target()) == CodeBuffer::SECT_NONE);
749 }
750
751
752 address external_word_Relocation::target() {
753 address target = _target;
754 if (target == nullptr) {
755 target = pd_get_address_from_code();
756 }
757 return target;
758 }
759
760
761 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
762 address target = _target;
763 if (target == nullptr) {
764 target = new_addr_for(this->target(), src, dest);
765 }
766 set_value(target);
767 }
768
769
770 address internal_word_Relocation::target() {
771 address target = _target;
772 if (target == nullptr) {
773 if (addr_in_const()) {
774 target = *(address*)addr();
775 } else {
776 target = pd_get_address_from_code();
777 }
778 }
779 return target;
780 }
781
782 //---------------------------------------------------------------------------------
783 // Non-product code
784
785 #ifndef PRODUCT
786
787 static const char* reloc_type_string(relocInfo::relocType t) {
788 switch (t) {
789 #define EACH_CASE(name) \
790 case relocInfo::name##_type: \
791 return #name;
792
793 APPLY_TO_RELOCATIONS(EACH_CASE);
794 #undef EACH_CASE
795
796 case relocInfo::none:
797 return "none";
798 case relocInfo::data_prefix_tag:
799 return "prefix";
800 default:
801 return "UNKNOWN RELOC TYPE";
802 }
803 }
804
805
806 void RelocIterator::print_current() {
807 if (!has_current()) {
808 tty->print_cr("(no relocs)");
809 return;
810 }
811 tty->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
812 p2i(_current), type(), reloc_type_string((relocInfo::relocType) type()), p2i(_addr), _current->addr_offset());
813 if (current()->format() != 0)
814 tty->print(" format=%d", current()->format());
815 if (datalen() == 1) {
816 tty->print(" data=%d", data()[0]);
817 } else if (datalen() > 0) {
818 tty->print(" data={");
819 for (int i = 0; i < datalen(); i++) {
820 tty->print("%04x", data()[i] & 0xFFFF);
821 }
822 tty->print("}");
823 }
824 tty->print("]");
825 switch (type()) {
826 case relocInfo::oop_type:
827 {
828 oop_Relocation* r = oop_reloc();
829 oop* oop_addr = nullptr;
830 oop raw_oop = nullptr;
831 oop oop_value = nullptr;
832 if (code() != nullptr || r->oop_is_immediate()) {
833 oop_addr = r->oop_addr();
834 raw_oop = *oop_addr;
835 oop_value = r->oop_value();
836 }
837 tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT "]",
838 p2i(oop_addr), p2i(raw_oop));
839 // Do not print the oop by default--we want this routine to
840 // work even during GC or other inconvenient times.
841 if (WizardMode && oop_value != nullptr) {
842 tty->print("oop_value=" INTPTR_FORMAT ": ", p2i(oop_value));
843 if (oopDesc::is_oop(oop_value)) {
844 oop_value->print_value_on(tty);
845 }
846 }
847 break;
848 }
849 case relocInfo::metadata_type:
850 {
851 metadata_Relocation* r = metadata_reloc();
852 Metadata** metadata_addr = nullptr;
853 Metadata* raw_metadata = nullptr;
854 Metadata* metadata_value = nullptr;
855 if (code() != nullptr || r->metadata_is_immediate()) {
856 metadata_addr = r->metadata_addr();
857 raw_metadata = *metadata_addr;
858 metadata_value = r->metadata_value();
859 }
860 tty->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT "]",
861 p2i(metadata_addr), p2i(raw_metadata));
862 if (metadata_value != nullptr) {
863 tty->print("metadata_value=" INTPTR_FORMAT ": ", p2i(metadata_value));
864 metadata_value->print_value_on(tty);
865 }
866 break;
867 }
868 case relocInfo::external_word_type:
869 case relocInfo::internal_word_type:
870 case relocInfo::section_word_type:
871 {
872 DataRelocation* r = (DataRelocation*) reloc();
873 tty->print(" | [target=" INTPTR_FORMAT "]", p2i(r->value())); //value==target
874 break;
875 }
876 case relocInfo::static_call_type:
877 {
878 static_call_Relocation* r = (static_call_Relocation*) reloc();
879 tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
880 p2i(r->destination()), p2i(r->method_value()));
881 CodeBlob* cb = CodeCache::find_blob(r->destination());
882 if (cb != nullptr) {
883 tty->print(" Blob::%s", cb->name());
884 }
885 break;
886 }
887 case relocInfo::runtime_call_type:
888 case relocInfo::runtime_call_w_cp_type:
889 {
890 CallRelocation* r = (CallRelocation*) reloc();
891 address dest = r->destination();
892 tty->print(" | [destination=" INTPTR_FORMAT "]", p2i(dest));
893 if (StubRoutines::contains(dest)) {
894 StubCodeDesc* desc = StubCodeDesc::desc_for(dest);
895 if (desc == nullptr) {
896 desc = StubCodeDesc::desc_for(dest + frame::pc_return_offset);
897 }
898 if (desc != nullptr) {
899 tty->print(" Stub::%s", desc->name());
900 }
901 } else {
902 CodeBlob* cb = CodeCache::find_blob(dest);
903 if (cb != nullptr) {
904 tty->print(" %s", cb->name());
905 } else {
906 ResourceMark rm;
907 const int buflen = 1024;
908 char* buf = NEW_RESOURCE_ARRAY(char, buflen);
909 int offset;
910 if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
911 tty->print(" %s", buf);
912 if (offset != 0) {
913 tty->print("+%d", offset);
914 }
915 }
916 }
917 }
918 break;
919 }
920 case relocInfo::virtual_call_type:
921 {
922 virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
923 tty->print(" | [destination=" INTPTR_FORMAT " cached_value=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
924 p2i(r->destination()), p2i(r->cached_value()), p2i(r->method_value()));
925 CodeBlob* cb = CodeCache::find_blob(r->destination());
926 if (cb != nullptr) {
927 tty->print(" Blob::%s", cb->name());
928 }
929 break;
930 }
931 case relocInfo::static_stub_type:
932 {
933 static_stub_Relocation* r = (static_stub_Relocation*) reloc();
934 tty->print(" | [static_call=" INTPTR_FORMAT "]", p2i(r->static_call()));
935 break;
936 }
937 case relocInfo::trampoline_stub_type:
938 {
939 trampoline_stub_Relocation* r = (trampoline_stub_Relocation*) reloc();
940 tty->print(" | [trampoline owner=" INTPTR_FORMAT "]", p2i(r->owner()));
941 break;
942 }
943 case relocInfo::opt_virtual_call_type:
944 {
945 opt_virtual_call_Relocation* r = (opt_virtual_call_Relocation*) reloc();
946 tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
947 p2i(r->destination()), p2i(r->method_value()));
948 CodeBlob* cb = CodeCache::find_blob(r->destination());
949 if (cb != nullptr) {
950 tty->print(" Blob::%s", cb->name());
951 }
952 break;
953 }
954 default:
955 break;
956 }
957 tty->cr();
958 }
959
960
961 void RelocIterator::print() {
962 RelocIterator save_this = (*this);
963 relocInfo* scan = _current;
964 if (!has_current()) scan += 1; // nothing to scan here!
965
966 bool skip_next = has_current();
967 bool got_next;
968 while (true) {
969 got_next = (skip_next || next());
970 skip_next = false;
971
972 tty->print(" @" INTPTR_FORMAT ": ", p2i(scan));
973 relocInfo* newscan = _current+1;
974 if (!has_current()) newscan -= 1; // nothing to scan here!
975 while (scan < newscan) {
976 tty->print("%04x", *(short*)scan & 0xFFFF);
977 scan++;
978 }
979 tty->cr();
980
981 if (!got_next) break;
982 print_current();
983 }
984
985 (*this) = save_this;
986 }
987
988 // For the debugger:
989 extern "C"
990 void print_blob_locs(nmethod* nm) {
991 nm->print();
992 RelocIterator iter(nm);
993 iter.print();
994 }
995 extern "C"
996 void print_buf_locs(CodeBuffer* cb) {
997 FlagSetting fs(PrintRelocations, true);
998 cb->print();
999 }
1000 #endif // !PRODUCT