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 "ci/ciUtilities.hpp"
26 #include "code/codeCache.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/relocInfo.hpp"
30 #include "code/SCCache.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "memory/universe.hpp"
33 #include "oops/compressedOops.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "runtime/flags/flagSetting.hpp"
36 #include "runtime/stubCodeGenerator.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/checkedCast.hpp"
39 #include "utilities/copy.hpp"
40
41 #include <new>
42 #include <type_traits>
43
44 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
45
46
47 // Implementation of relocInfo
48
49 #ifdef ASSERT
50 relocInfo::relocType relocInfo::check_relocType(relocType type) {
51 assert(type != data_prefix_tag, "cannot build a prefix this way");
52 assert((type & type_mask) == type, "wrong type");
53 return type;
54 }
55
56 void relocInfo::check_offset_and_format(int offset, int format) {
57 assert(offset >= 0 && offset < offset_limit(), "offset out off bounds");
58 assert(is_aligned(offset, offset_unit), "misaligned offset");
59 assert((format & format_mask) == format, "wrong format");
60 }
61 #endif // ASSERT
62
63 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
64 relocInfo* data = this+1; // here's where the data might go
65 dest->set_locs_end(data); // sync end: the next call may read dest.locs_end
66 reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
67 relocInfo* data_limit = dest->locs_end();
68 if (data_limit > data) {
69 relocInfo suffix = (*this);
70 data_limit = this->finish_prefix((short*) data_limit);
71 // Finish up with the suffix. (Hack note: pack_data_to might edit this.)
72 *data_limit = suffix;
73 dest->set_locs_end(data_limit+1);
74 }
75 }
76
77 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
78 assert(sizeof(relocInfo) == sizeof(short), "change this code");
79 short* p = (short*)(this+1);
80 assert(prefix_limit >= p, "must be a valid span of data");
81 int plen = checked_cast<int>(prefix_limit - p);
82 if (plen == 0) {
83 debug_only(_value = 0xFFFF);
84 return this; // no data: remove self completely
85 }
86 if (plen == 1 && fits_into_immediate(p[0])) {
87 (*this) = immediate_relocInfo(p[0]); // move data inside self
88 return this+1;
89 }
90 // cannot compact, so just update the count and return the limit pointer
91 (*this) = prefix_info(plen); // write new datalen
92 assert(data() + datalen() == prefix_limit, "pointers must line up");
93 return (relocInfo*)prefix_limit;
94 }
95
96 void relocInfo::set_type(relocType t) {
97 int old_offset = addr_offset();
98 int old_format = format();
99 (*this) = relocInfo(t, old_offset, old_format);
100 assert(type()==(int)t, "sanity check");
101 assert(addr_offset()==old_offset, "sanity check");
102 assert(format()==old_format, "sanity check");
103 }
104
105 void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
106 bool found = false;
107 while (itr->next() && !found) {
108 if (itr->addr() == pc) {
109 assert(itr->type()==old_type, "wrong relocInfo type found");
110 itr->current()->set_type(new_type);
111 found=true;
112 }
113 }
114 assert(found, "no relocInfo found for pc");
115 }
116
117
118 // ----------------------------------------------------------------------------------------------------
119 // Implementation of RelocIterator
120
121 void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
122 initialize_misc();
123
124 if (nm == nullptr && begin != nullptr) {
125 // allow nmethod to be deduced from beginning address
126 CodeBlob* cb = CodeCache::find_blob(begin);
127 nm = (cb != nullptr) ? cb->as_nmethod_or_null() : nullptr;
128 }
129 guarantee(nm != nullptr, "must be able to deduce nmethod from other arguments");
130
131 _code = nm;
132 _current = nm->relocation_begin() - 1;
133 _end = nm->relocation_end();
134 _addr = nm->content_begin();
135
136 // Initialize code sections.
137 _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
138 _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
139 _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin() ;
140
141 _section_end [CodeBuffer::SECT_CONSTS] = nm->consts_end() ;
142 _section_end [CodeBuffer::SECT_INSTS ] = nm->insts_end() ;
143 _section_end [CodeBuffer::SECT_STUBS ] = nm->stub_end() ;
144
145 assert(!has_current(), "just checking");
146 assert(begin == nullptr || begin >= nm->code_begin(), "in bounds");
147 assert(limit == nullptr || limit <= nm->code_end(), "in bounds");
148 set_limits(begin, limit);
149 }
150
151
152 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
153 initialize_misc();
154 assert(((cs->locs_start() != nullptr) && (cs->locs_end() != nullptr)), "valid start and end pointer");
155 _current = cs->locs_start()-1;
156 _end = cs->locs_end();
157 _addr = cs->start();
158 _code = nullptr; // Not cb->blob();
159
160 CodeBuffer* cb = cs->outer();
161 assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
162 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
163 CodeSection* cs = cb->code_section(n);
164 _section_start[n] = cs->start();
165 _section_end [n] = cs->end();
166 }
167
168 assert(!has_current(), "just checking");
169
170 assert(begin == nullptr || begin >= cs->start(), "in bounds");
171 assert(limit == nullptr || limit <= cs->end(), "in bounds");
172 set_limits(begin, limit);
173 }
174
175 bool RelocIterator::addr_in_const() const {
176 const int n = CodeBuffer::SECT_CONSTS;
177 if (_section_start[n] == nullptr) {
178 return false;
179 }
180 return section_start(n) <= addr() && addr() < section_end(n);
181 }
182
183
184 void RelocIterator::set_limits(address begin, address limit) {
185 _limit = limit;
186
187 // the limit affects this next stuff:
188 if (begin != nullptr) {
189 relocInfo* backup;
190 address backup_addr;
191 while (true) {
192 backup = _current;
193 backup_addr = _addr;
194 if (!next() || addr() >= begin) break;
195 }
196 // At this point, either we are at the first matching record,
197 // or else there is no such record, and !has_current().
198 // In either case, revert to the immediately preceding state.
199 _current = backup;
200 _addr = backup_addr;
201 set_has_current(false);
202 }
203 }
204
205
206 // All the strange bit-encodings are in here.
207 // The idea is to encode relocation data which are small integers
208 // very efficiently (a single extra halfword). Larger chunks of
209 // relocation data need a halfword header to hold their size.
210 void RelocIterator::advance_over_prefix() {
211 if (_current->is_datalen()) {
212 _data = (short*) _current->data();
213 _datalen = _current->datalen();
214 _current += _datalen + 1; // skip the embedded data & header
215 } else {
216 _databuf = _current->immediate();
217 _data = &_databuf;
218 _datalen = 1;
219 _current++; // skip the header
220 }
221 // The client will see the following relocInfo, whatever that is.
222 // It is the reloc to which the preceding data applies.
223 }
224
225
226 void RelocIterator::initialize_misc() {
227 set_has_current(false);
228 for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
229 _section_start[i] = nullptr; // these will be lazily computed, if needed
230 _section_end [i] = nullptr;
231 }
232 }
233
234
235 Relocation* RelocIterator::reloc() {
236 // (take the "switch" out-of-line)
237 relocInfo::relocType t = type();
238 if (false) {}
239 #define EACH_TYPE(name) \
240 else if (t == relocInfo::name##_type) { \
241 return name##_reloc(); \
242 }
243 APPLY_TO_RELOCATIONS(EACH_TYPE);
244 #undef EACH_TYPE
245 assert(t == relocInfo::none, "must be padding");
246 _rh = RelocationHolder::none;
247 return _rh.reloc();
248 }
249
250 // Verify all the destructors are trivial, so we don't need to worry about
251 // destroying old contents of a RelocationHolder being assigned or destroyed.
252 #define VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Reloc) \
253 static_assert(std::is_trivially_destructible<Reloc>::value, "must be");
254
255 #define VERIFY_TRIVIALLY_DESTRUCTIBLE(name) \
256 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(PASTE_TOKENS(name, _Relocation));
257
258 APPLY_TO_RELOCATIONS(VERIFY_TRIVIALLY_DESTRUCTIBLE)
259 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Relocation)
260
261 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX
262 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE
263
264 // Define all the copy_into functions. These rely on all Relocation types
265 // being trivially destructible (verified above). So it doesn't matter
266 // whether the target holder has been previously initialized or not. There's
267 // no need to consider that distinction and destruct the relocation in an
268 // already initialized holder.
269 #define DEFINE_COPY_INTO_AUX(Reloc) \
270 void Reloc::copy_into(RelocationHolder& holder) const { \
271 copy_into_helper(*this, holder); \
272 }
273
274 #define DEFINE_COPY_INTO(name) \
275 DEFINE_COPY_INTO_AUX(PASTE_TOKENS(name, _Relocation))
276
277 APPLY_TO_RELOCATIONS(DEFINE_COPY_INTO)
278 DEFINE_COPY_INTO_AUX(Relocation)
279
280 #undef DEFINE_COPY_INTO_AUX
281 #undef DEFINE_COPY_INTO
282
283 //////// Methods for flyweight Relocation types
284
285 // some relocations can compute their own values
286 address Relocation::value() {
287 ShouldNotReachHere();
288 return nullptr;
289 }
290
291
292 void Relocation::set_value(address x) {
293 ShouldNotReachHere();
294 }
295
296 void Relocation::const_set_data_value(address x) {
297 #ifdef _LP64
298 if (format() == relocInfo::narrow_oop_in_const) {
299 *(narrowOop*)addr() = CompressedOops::encode(cast_to_oop(x));
300 } else {
301 #endif
302 *(address*)addr() = x;
303 #ifdef _LP64
304 }
305 #endif
306 }
307
308 void Relocation::const_verify_data_value(address x) {
309 #ifdef _LP64
310 if (format() == relocInfo::narrow_oop_in_const) {
311 guarantee(*(narrowOop*)addr() == CompressedOops::encode(cast_to_oop(x)), "must agree");
312 } else {
313 #endif
314 guarantee(*(address*)addr() == x, "must agree");
315 #ifdef _LP64
316 }
317 #endif
318 }
319
320
321 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
322 if (rtype == relocInfo::none) return RelocationHolder::none;
323 relocInfo ri = relocInfo(rtype, 0);
324 RelocIterator itr;
325 itr.set_current(ri);
326 itr.reloc();
327 return itr._rh;
328 }
329
330 address Relocation::old_addr_for(address newa,
331 const CodeBuffer* src, CodeBuffer* dest) {
332 int sect = dest->section_index_of(newa);
333 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
334 address ostart = src->code_section(sect)->start();
335 address nstart = dest->code_section(sect)->start();
336 return ostart + (newa - nstart);
337 }
338
339 address Relocation::new_addr_for(address olda,
340 const CodeBuffer* src, CodeBuffer* dest) {
341 debug_only(const CodeBuffer* src0 = src);
342 int sect = CodeBuffer::SECT_NONE;
343 // Look for olda in the source buffer, and all previous incarnations
344 // if the source buffer has been expanded.
345 for (; src != nullptr; src = src->before_expand()) {
346 sect = src->section_index_of(olda);
347 if (sect != CodeBuffer::SECT_NONE) break;
348 }
349 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
350 address ostart = src->code_section(sect)->start();
351 address nstart = dest->code_section(sect)->start();
352 return nstart + (olda - ostart);
353 }
354
355 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
356 address addr0 = addr;
357 if (addr0 == nullptr || dest->allocates2(addr0)) return;
358 CodeBuffer* cb = dest->outer();
359 addr = new_addr_for(addr0, cb, cb);
360 assert(allow_other_sections || dest->contains2(addr),
361 "addr must be in required section");
362 }
363
364
365 void CallRelocation::set_destination(address x) {
366 pd_set_call_destination(x);
367 }
368
369 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
370 // Usually a self-relative reference to an external routine.
371 // On some platforms, the reference is absolute (not self-relative).
372 // The enhanced use of pd_call_destination sorts this all out.
373 address orig_addr = old_addr_for(addr(), src, dest);
374 address callee = pd_call_destination(orig_addr);
375 // Reassert the callee address, this time in the new copy of the code.
376 pd_set_call_destination(callee);
377 }
378
379
380 #ifdef USE_TRAMPOLINE_STUB_FIX_OWNER
381 void trampoline_stub_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
382 // Finalize owner destination only for nmethods
383 if (dest->blob() != nullptr) return;
384 pd_fix_owner_after_move();
385 }
386 #endif
387
388 //// pack/unpack methods
389
390 void oop_Relocation::pack_data_to(CodeSection* dest) {
391 short* p = (short*) dest->locs_end();
392 p = pack_1_int_to(p, _oop_index);
393 dest->set_locs_end((relocInfo*) p);
394 }
395
396
397 void oop_Relocation::unpack_data() {
398 _oop_index = unpack_1_int();
399 }
400
401 void metadata_Relocation::pack_data_to(CodeSection* dest) {
402 short* p = (short*) dest->locs_end();
403 p = pack_1_int_to(p, _metadata_index);
404 dest->set_locs_end((relocInfo*) p);
405 }
406
407
408 void metadata_Relocation::unpack_data() {
409 _metadata_index = unpack_1_int();
410 }
411
412
413 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
414 short* p = (short*) dest->locs_end();
415 address point = dest->locs_point();
416
417 normalize_address(_cached_value, dest);
418 jint x0 = scaled_offset_null_special(_cached_value, point);
419 p = pack_2_ints_to(p, x0, _method_index);
420 dest->set_locs_end((relocInfo*) p);
421 }
422
423
424 void virtual_call_Relocation::unpack_data() {
425 jint x0 = 0;
426 unpack_2_ints(x0, _method_index);
427 address point = addr();
428 _cached_value = x0==0? nullptr: address_from_scaled_offset(x0, point);
429 }
430
431 void runtime_call_w_cp_Relocation::pack_data_to(CodeSection * dest) {
432 short* p = pack_1_int_to((short *)dest->locs_end(), (jint)(_offset >> 2));
433 dest->set_locs_end((relocInfo*) p);
434 }
435
436 void runtime_call_w_cp_Relocation::unpack_data() {
437 _offset = unpack_1_int() << 2;
438 }
439
440 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
441 short* p = (short*) dest->locs_end();
442 CodeSection* insts = dest->outer()->insts();
443 normalize_address(_static_call, insts);
444 p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
445 dest->set_locs_end((relocInfo*) p);
446 }
447
448 void static_stub_Relocation::unpack_data() {
449 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
450 jint offset = unpack_1_int();
451 _static_call = address_from_scaled_offset(offset, base);
452 }
453
454 void trampoline_stub_Relocation::pack_data_to(CodeSection* dest ) {
455 short* p = (short*) dest->locs_end();
456 CodeSection* insts = dest->outer()->insts();
457 normalize_address(_owner, insts);
458 p = pack_1_int_to(p, scaled_offset(_owner, insts->start()));
459 dest->set_locs_end((relocInfo*) p);
460 }
461
462 void trampoline_stub_Relocation::unpack_data() {
463 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
464 _owner = address_from_scaled_offset(unpack_1_int(), base);
465 }
466
467 void external_word_Relocation::pack_data_to(CodeSection* dest) {
468 short* p = (short*) dest->locs_end();
469 int index = ExternalsRecorder::find_index(_target);
470 // Use 4 bytes to store index to be able patch it when
471 // updating relocations in SCCReader::read_relocations().
472 p = add_jint(p, index);
473 dest->set_locs_end((relocInfo*) p);
474 }
475
476 void external_word_Relocation::unpack_data() {
477 int index = unpack_1_int();
478 _target = ExternalsRecorder::at(index);
479 }
480
481
482 void internal_word_Relocation::pack_data_to(CodeSection* dest) {
483 short* p = (short*) dest->locs_end();
484 normalize_address(_target, dest, true);
485
486 // Check whether my target address is valid within this section.
487 // If not, strengthen the relocation type to point to another section.
488 int sindex = _section;
489 if (sindex == CodeBuffer::SECT_NONE && _target != nullptr
490 && (!dest->allocates(_target) || _target == dest->locs_point())) {
491 sindex = dest->outer()->section_index_of(_target);
492 guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
493 relocInfo* base = dest->locs_end() - 1;
494 assert(base->type() == this->type(), "sanity");
495 // Change the written type, to be section_word_type instead.
496 base->set_type(relocInfo::section_word_type);
497 }
498
499 // Note: An internal_word relocation cannot refer to its own instruction,
500 // because we reserve "0" to mean that the pointer itself is embedded
501 // in the code stream. We use a section_word relocation for such cases.
502
503 if (sindex == CodeBuffer::SECT_NONE) {
504 assert(type() == relocInfo::internal_word_type, "must be base class");
505 guarantee(_target == nullptr || dest->allocates2(_target), "must be within the given code section");
506 jint x0 = scaled_offset_null_special(_target, dest->locs_point());
507 assert(!(x0 == 0 && _target != nullptr), "correct encoding of null target");
508 p = pack_1_int_to(p, x0);
509 } else {
510 assert(_target != nullptr, "sanity");
511 CodeSection* sect = dest->outer()->code_section(sindex);
512 guarantee(sect->allocates2(_target), "must be in correct section");
513 address base = sect->start();
514 jint offset = scaled_offset(_target, base);
515 assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
516 assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
517 p = pack_1_int_to(p, (offset << section_width) | sindex);
518 }
519
520 dest->set_locs_end((relocInfo*) p);
521 }
522
523
524 void internal_word_Relocation::unpack_data() {
525 jint x0 = unpack_1_int();
526 _target = x0==0? nullptr: address_from_scaled_offset(x0, addr());
527 _section = CodeBuffer::SECT_NONE;
528 }
529
530
531 void section_word_Relocation::unpack_data() {
532 jint x = unpack_1_int();
533 jint offset = (x >> section_width);
534 int sindex = (x & ((1<<section_width)-1));
535 address base = binding()->section_start(sindex);
536
537 _section = sindex;
538 _target = address_from_scaled_offset(offset, base);
539 }
540
541 //// miscellaneous methods
542 oop* oop_Relocation::oop_addr() {
543 int n = _oop_index;
544 if (n == 0) {
545 // oop is stored in the code stream
546 return (oop*) pd_address_in_code();
547 } else {
548 // oop is stored in table at nmethod::oops_begin
549 return code()->oop_addr_at(n);
550 }
551 }
552
553
554 oop oop_Relocation::oop_value() {
555 // clean inline caches store a special pseudo-null
556 if (Universe::contains_non_oop_word(oop_addr())) {
557 return nullptr;
558 }
559 return *oop_addr();
560 }
561
562
563 void oop_Relocation::fix_oop_relocation() {
564 if (!oop_is_immediate()) {
565 // get the oop from the pool, and re-insert it into the instruction:
566 set_value(value());
567 }
568 }
569
570
571 void oop_Relocation::verify_oop_relocation() {
572 if (!oop_is_immediate()) {
573 // get the oop from the pool, and re-insert it into the instruction:
574 verify_value(value());
575 }
576 }
577
578 // meta data versions
579 Metadata** metadata_Relocation::metadata_addr() {
580 int n = _metadata_index;
581 if (n == 0) {
582 // metadata is stored in the code stream
583 return (Metadata**) pd_address_in_code();
584 } else {
585 // metadata is stored in table at nmethod::metadatas_begin
586 return code()->metadata_addr_at(n);
587 }
588 }
589
590
591 Metadata* metadata_Relocation::metadata_value() {
592 Metadata* v = *metadata_addr();
593 // clean inline caches store a special pseudo-null
594 if (v == (Metadata*)Universe::non_oop_word()) v = nullptr;
595 return v;
596 }
597
598
599 void metadata_Relocation::fix_metadata_relocation() {
600 if (!metadata_is_immediate()) {
601 // get the metadata from the pool, and re-insert it into the instruction:
602 pd_fix_value(value());
603 }
604 }
605
606 address virtual_call_Relocation::cached_value() {
607 assert(_cached_value != nullptr && _cached_value < addr(), "must precede ic_call");
608 return _cached_value;
609 }
610
611 Method* virtual_call_Relocation::method_value() {
612 nmethod* nm = code();
613 if (nm == nullptr) return (Method*)nullptr;
614 Metadata* m = nm->metadata_at(_method_index);
615 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
616 assert(m == nullptr || m->is_method(), "not a method");
617 return (Method*)m;
618 }
619
620 void virtual_call_Relocation::clear_inline_cache() {
621 ResourceMark rm;
622 CompiledIC* icache = CompiledIC_at(this);
623 icache->set_to_clean();
624 }
625
626
627 void opt_virtual_call_Relocation::pack_data_to(CodeSection* dest) {
628 short* p = (short*) dest->locs_end();
629 p = pack_1_int_to(p, _method_index);
630 dest->set_locs_end((relocInfo*) p);
631 }
632
633 void opt_virtual_call_Relocation::unpack_data() {
634 _method_index = unpack_1_int();
635 }
636
637 Method* opt_virtual_call_Relocation::method_value() {
638 nmethod* nm = code();
639 if (nm == nullptr) return (Method*)nullptr;
640 Metadata* m = nm->metadata_at(_method_index);
641 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
642 assert(m == nullptr || m->is_method(), "not a method");
643 return (Method*)m;
644 }
645
646 void opt_virtual_call_Relocation::clear_inline_cache() {
647 ResourceMark rm;
648 CompiledDirectCall* callsite = CompiledDirectCall::at(this);
649 callsite->set_to_clean();
650 }
651
652 address opt_virtual_call_Relocation::static_stub() {
653 // search for the static stub who points back to this static call
654 address static_call_addr = addr();
655 RelocIterator iter(code());
656 while (iter.next()) {
657 if (iter.type() == relocInfo::static_stub_type) {
658 static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
659 if (stub_reloc->static_call() == static_call_addr) {
660 return iter.addr();
661 }
662 }
663 }
664 return nullptr;
665 }
666
667 Method* static_call_Relocation::method_value() {
668 nmethod* nm = code();
669 if (nm == nullptr) return (Method*)nullptr;
670 Metadata* m = nm->metadata_at(_method_index);
671 assert(m != nullptr || _method_index == 0, "should be non-null for non-zero index");
672 assert(m == nullptr || m->is_method(), "not a method");
673 return (Method*)m;
674 }
675
676 void static_call_Relocation::pack_data_to(CodeSection* dest) {
677 short* p = (short*) dest->locs_end();
678 p = pack_1_int_to(p, _method_index);
679 dest->set_locs_end((relocInfo*) p);
680 }
681
682 void static_call_Relocation::unpack_data() {
683 _method_index = unpack_1_int();
684 }
685
686 void static_call_Relocation::clear_inline_cache() {
687 ResourceMark rm;
688 CompiledDirectCall* callsite = CompiledDirectCall::at(this);
689 callsite->set_to_clean();
690 }
691
692
693 address static_call_Relocation::static_stub() {
694 // search for the static stub who points back to this static call
695 address static_call_addr = addr();
696 RelocIterator iter(code());
697 while (iter.next()) {
698 if (iter.type() == relocInfo::static_stub_type) {
699 static_stub_Relocation* stub_reloc = iter.static_stub_reloc();
700 if (stub_reloc->static_call() == static_call_addr) {
701 return iter.addr();
702 }
703 }
704 }
705 return nullptr;
706 }
707
708 // Finds the trampoline address for a call. If no trampoline stub is
709 // found nullptr is returned which can be handled by the caller.
710 address trampoline_stub_Relocation::get_trampoline_for(address call, nmethod* code) {
711 // There are no relocations available when the code gets relocated
712 // because of CodeBuffer expansion.
713 if (code->relocation_size() == 0)
714 return nullptr;
715
716 RelocIterator iter(code, call);
717 while (iter.next()) {
718 if (iter.type() == relocInfo::trampoline_stub_type) {
719 if (iter.trampoline_stub_reloc()->owner() == call) {
720 return iter.addr();
721 }
722 }
723 }
724
725 return nullptr;
726 }
727
728 void static_stub_Relocation::clear_inline_cache() {
729 // Call stub is only used when calling the interpreted code.
730 // It does not really need to be cleared, except that we want to clean out the methodoop.
731 CompiledDirectCall::set_stub_to_clean(this);
732 }
733
734
735 void external_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
736 if (_target != nullptr) {
737 // Probably this reference is absolute, not relative, so the following is
738 // probably a no-op.
739 set_value(_target);
740 }
741 // If target is nullptr, this is an absolute embedded reference to an external
742 // location, which means there is nothing to fix here. In either case, the
743 // resulting target should be an "external" address.
744 #ifdef ASSERT
745 if (SCCache::is_on()) {
746 // SCA needs relocation info for card table base which may point to CodeCache
747 if (is_card_table_address(target())) {
748 return;
749 }
750 }
751 #endif
752 postcond(src->section_index_of(target()) == CodeBuffer::SECT_NONE);
753 postcond(dest->section_index_of(target()) == CodeBuffer::SECT_NONE);
754 }
755
756
757 address external_word_Relocation::target() {
758 address target = _target;
759 if (target == nullptr) {
760 target = pd_get_address_from_code();
761 }
762 return target;
763 }
764
765
766 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
767 address target = _target;
768 if (target == nullptr) {
769 target = new_addr_for(this->target(), src, dest);
770 }
771 set_value(target);
772 }
773
774
775 address internal_word_Relocation::target() {
776 address target = _target;
777 if (target == nullptr) {
778 if (addr_in_const()) {
779 target = *(address*)addr();
780 } else {
781 target = pd_get_address_from_code();
782 }
783 }
784 return target;
785 }
786
787 const char* relocInfo::type_name(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_on(outputStream* st) {
807 if (!has_current()) {
808 st->print_cr("(no relocs)");
809 return;
810 }
811 st->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
812 p2i(_current), type(), relocInfo::type_name(type()), p2i(_addr), _current->addr_offset());
813 if (current()->format() != 0)
814 st->print(" format=%d", current()->format());
815 if (datalen() == 1) {
816 st->print(" data=%d", data()[0]);
817 } else if (datalen() > 0) {
818 st->print(" data={");
819 for (int i = 0; i < datalen(); i++) {
820 st->print("%04x", data()[i] & 0xFFFF);
821 }
822 st->print("}");
823 }
824 st->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 st->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " index=%d]",
838 p2i(oop_addr), p2i(raw_oop), r->oop_index());
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 st->print("oop_value=" INTPTR_FORMAT ": ", p2i(oop_value));
843 if (oopDesc::is_oop(oop_value)) {
844 oop_value->print_value_on(st);
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 st->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " index=%d]",
861 p2i(metadata_addr), p2i(raw_metadata), r->metadata_index());
862 if (metadata_value != nullptr) {
863 st->print("metadata_value=" INTPTR_FORMAT ": ", p2i(metadata_value));
864 metadata_value->print_value_on(st);
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 st->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 st->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 st->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 st->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 st->print(" Stub::%s", desc->name());
900 }
901 } else {
902 CodeBlob* cb = CodeCache::find_blob(dest);
903 if (cb != nullptr) {
904 st->print(" Blob::%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 st->print(" %s", buf);
912 if (offset != 0) {
913 st->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 st->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 st->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 st->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 st->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 st->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 st->print(" Blob::%s", cb->name());
951 }
952 break;
953 }
954 default:
955 break;
956 }
957 st->cr();
958 }
959
960
961 void RelocIterator::print_on(outputStream* st) {
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 st->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 st->print("%04x", *(short*)scan & 0xFFFF);
977 scan++;
978 }
979 st->cr();
980
981 if (!got_next) break;
982 print_current_on(st);
983 }
984
985 (*this) = save_this;
986 }
987
988 //---------------------------------------------------------------------------------
989 // Non-product code
990
991 #ifndef PRODUCT
992
993 // For the debugger:
994 extern "C"
995 void print_blob_locs(nmethod* nm) {
996 nm->print();
997 RelocIterator iter(nm);
998 iter.print_on(tty);
999 }
1000 extern "C"
1001 void print_buf_locs(CodeBuffer* cb) {
1002 FlagSetting fs(PrintRelocations, true);
1003 cb->print_on(tty);
1004 }
1005 #endif // !PRODUCT