1 /*
2 * Copyright (c) 1997, 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 "code/codeCache.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/relocInfo.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "memory/universe.hpp"
32 #include "oops/compressedOops.inline.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/flags/flagSetting.hpp"
35 #include "runtime/stubCodeGenerator.hpp"
36 #include "utilities/align.hpp"
37 #include "utilities/checkedCast.hpp"
38 #include "utilities/copy.hpp"
39
40 #include <new>
41 #include <type_traits>
42
43 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
44
45
46 // Implementation of relocInfo
47
48 #ifdef ASSERT
49 relocInfo::relocType relocInfo::check_relocType(relocType type) {
50 assert(type != data_prefix_tag, "cannot build a prefix this way");
51 assert((type & type_mask) == type, "wrong type");
52 return type;
53 }
54
55 void relocInfo::check_offset_and_format(int offset, int format) {
56 assert(offset >= 0 && offset < offset_limit(), "offset out off bounds");
57 assert(is_aligned(offset, offset_unit), "misaligned offset");
58 assert((format & format_mask) == format, "wrong format");
59 }
60 #endif // ASSERT
61
62 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
63 relocInfo* data = this+1; // here's where the data might go
64 dest->set_locs_end(data); // sync end: the next call may read dest.locs_end
65 reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
66 relocInfo* data_limit = dest->locs_end();
67 if (data_limit > data) {
68 relocInfo suffix = (*this);
69 data_limit = this->finish_prefix((short*) data_limit);
70 // Finish up with the suffix. (Hack note: pack_data_to might edit this.)
71 *data_limit = suffix;
72 dest->set_locs_end(data_limit+1);
73 }
74 }
75
76 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
77 assert(sizeof(relocInfo) == sizeof(short), "change this code");
78 short* p = (short*)(this+1);
79 assert(prefix_limit >= p, "must be a valid span of data");
80 int plen = checked_cast<int>(prefix_limit - p);
81 if (plen == 0) {
82 debug_only(_value = 0xFFFF);
83 return this; // no data: remove self completely
84 }
85 if (plen == 1 && fits_into_immediate(p[0])) {
86 (*this) = immediate_relocInfo(p[0]); // move data inside self
87 return this+1;
88 }
89 // cannot compact, so just update the count and return the limit pointer
90 (*this) = prefix_info(plen); // write new datalen
91 assert(data() + datalen() == prefix_limit, "pointers must line up");
92 return (relocInfo*)prefix_limit;
93 }
94
95 void relocInfo::set_type(relocType t) {
96 int old_offset = addr_offset();
97 int old_format = format();
98 (*this) = relocInfo(t, old_offset, old_format);
99 assert(type()==(int)t, "sanity check");
100 assert(addr_offset()==old_offset, "sanity check");
101 assert(format()==old_format, "sanity check");
102 }
103
104 void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
105 bool found = false;
106 while (itr->next() && !found) {
107 if (itr->addr() == pc) {
108 assert(itr->type()==old_type, "wrong relocInfo type found");
109 itr->current()->set_type(new_type);
110 found=true;
111 }
112 }
113 assert(found, "no relocInfo found for pc");
114 }
115
116
117 // ----------------------------------------------------------------------------------------------------
118 // Implementation of RelocIterator
119
120 void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
121 initialize_misc();
122
123 if (nm == nullptr && begin != nullptr) {
124 // allow nmethod to be deduced from beginning address
125 CodeBlob* cb = CodeCache::find_blob(begin);
126 nm = (cb != nullptr) ? cb->as_nmethod_or_null() : nullptr;
127 }
128 guarantee(nm != nullptr, "must be able to deduce nmethod from other arguments");
129
130 _code = nm;
131 _current = nm->relocation_begin() - 1;
132 _end = nm->relocation_end();
133 _addr = nm->content_begin();
134
135 // Initialize code sections.
136 _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
137 _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
138 _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin() ;
139
140 _section_end [CodeBuffer::SECT_CONSTS] = nm->consts_end() ;
141 _section_end [CodeBuffer::SECT_INSTS ] = nm->insts_end() ;
142 _section_end [CodeBuffer::SECT_STUBS ] = nm->stub_end() ;
143
144 assert(!has_current(), "just checking");
145 assert(begin == nullptr || begin >= nm->code_begin(), "in bounds");
146 assert(limit == nullptr || limit <= nm->code_end(), "in bounds");
147 set_limits(begin, limit);
148 }
149
150
151 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
152 initialize_misc();
153 assert(((cs->locs_start() != nullptr) && (cs->locs_end() != nullptr)) ||
154 ((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 return section_start(n) <= addr() && addr() < section_end(n);
178 }
179
180
181 void RelocIterator::set_limits(address begin, address limit) {
182 _limit = limit;
183
184 // the limit affects this next stuff:
185 if (begin != nullptr) {
186 relocInfo* backup;
187 address backup_addr;
188 while (true) {
189 backup = _current;
190 backup_addr = _addr;
191 if (!next() || addr() >= begin) break;
192 }
193 // At this point, either we are at the first matching record,
194 // or else there is no such record, and !has_current().
195 // In either case, revert to the immediately preceding state.
196 _current = backup;
197 _addr = backup_addr;
198 set_has_current(false);
199 }
200 }
201
202
203 // All the strange bit-encodings are in here.
204 // The idea is to encode relocation data which are small integers
205 // very efficiently (a single extra halfword). Larger chunks of
206 // relocation data need a halfword header to hold their size.
207 void RelocIterator::advance_over_prefix() {
208 if (_current->is_datalen()) {
209 _data = (short*) _current->data();
210 _datalen = _current->datalen();
211 _current += _datalen + 1; // skip the embedded data & header
212 } else {
213 _databuf = _current->immediate();
214 _data = &_databuf;
215 _datalen = 1;
216 _current++; // skip the header
217 }
218 // The client will see the following relocInfo, whatever that is.
219 // It is the reloc to which the preceding data applies.
220 }
221
222
223 void RelocIterator::initialize_misc() {
224 set_has_current(false);
225 for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
226 _section_start[i] = nullptr; // these will be lazily computed, if needed
227 _section_end [i] = nullptr;
228 }
229 }
230
231
232 Relocation* RelocIterator::reloc() {
233 // (take the "switch" out-of-line)
234 relocInfo::relocType t = type();
235 if (false) {}
236 #define EACH_TYPE(name) \
237 else if (t == relocInfo::name##_type) { \
238 return name##_reloc(); \
239 }
240 APPLY_TO_RELOCATIONS(EACH_TYPE);
241 #undef EACH_TYPE
242 assert(t == relocInfo::none, "must be padding");
243 _rh = RelocationHolder::none;
244 return _rh.reloc();
245 }
246
247 // Verify all the destructors are trivial, so we don't need to worry about
248 // destroying old contents of a RelocationHolder being assigned or destroyed.
249 #define VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Reloc) \
250 static_assert(std::is_trivially_destructible<Reloc>::value, "must be");
251
252 #define VERIFY_TRIVIALLY_DESTRUCTIBLE(name) \
253 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(PASTE_TOKENS(name, _Relocation));
254
255 APPLY_TO_RELOCATIONS(VERIFY_TRIVIALLY_DESTRUCTIBLE)
256 VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX(Relocation)
257
258 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE_AUX
259 #undef VERIFY_TRIVIALLY_DESTRUCTIBLE
260
261 // Define all the copy_into functions. These rely on all Relocation types
262 // being trivially destructible (verified above). So it doesn't matter
263 // whether the target holder has been previously initialized or not. There's
264 // no need to consider that distinction and destruct the relocation in an
265 // already initialized holder.
266 #define DEFINE_COPY_INTO_AUX(Reloc) \
267 void Reloc::copy_into(RelocationHolder& holder) const { \
268 copy_into_helper(*this, holder); \
269 }
270
271 #define DEFINE_COPY_INTO(name) \
272 DEFINE_COPY_INTO_AUX(PASTE_TOKENS(name, _Relocation))
273
274 APPLY_TO_RELOCATIONS(DEFINE_COPY_INTO)
275 DEFINE_COPY_INTO_AUX(Relocation)
276
277 #undef DEFINE_COPY_INTO_AUX
278 #undef DEFINE_COPY_INTO
279
280 //////// Methods for flyweight Relocation types
281
282 // some relocations can compute their own values
283 address Relocation::value() {
284 ShouldNotReachHere();
285 return nullptr;
286 }
287
288
289 void Relocation::set_value(address x) {
290 ShouldNotReachHere();
291 }
292
293 void Relocation::const_set_data_value(address x) {
294 #ifdef _LP64
295 if (format() == relocInfo::narrow_oop_in_const) {
296 *(narrowOop*)addr() = CompressedOops::encode(cast_to_oop(x));
297 } else {
298 #endif
299 *(address*)addr() = x;
300 #ifdef _LP64
301 }
302 #endif
303 }
304
305 void Relocation::const_verify_data_value(address x) {
306 #ifdef _LP64
307 if (format() == relocInfo::narrow_oop_in_const) {
308 guarantee(*(narrowOop*)addr() == CompressedOops::encode(cast_to_oop(x)), "must agree");
309 } else {
310 #endif
311 guarantee(*(address*)addr() == x, "must agree");
312 #ifdef _LP64
313 }
314 #endif
315 }
316
317
318 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
319 if (rtype == relocInfo::none) return RelocationHolder::none;
320 relocInfo ri = relocInfo(rtype, 0);
321 RelocIterator itr;
322 itr.set_current(ri);
323 itr.reloc();
324 return itr._rh;
325 }
326
327 address Relocation::old_addr_for(address newa,
328 const CodeBuffer* src, CodeBuffer* dest) {
329 int sect = dest->section_index_of(newa);
330 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
331 address ostart = src->code_section(sect)->start();
332 address nstart = dest->code_section(sect)->start();
333 return ostart + (newa - nstart);
334 }
335
336 address Relocation::new_addr_for(address olda,
337 const CodeBuffer* src, CodeBuffer* dest) {
338 debug_only(const CodeBuffer* src0 = src);
339 int sect = CodeBuffer::SECT_NONE;
340 // Look for olda in the source buffer, and all previous incarnations
341 // if the source buffer has been expanded.
342 for (; src != nullptr; src = src->before_expand()) {
343 sect = src->section_index_of(olda);
344 if (sect != CodeBuffer::SECT_NONE) break;
345 }
346 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
347 address ostart = src->code_section(sect)->start();
348 address nstart = dest->code_section(sect)->start();
349 return nstart + (olda - ostart);
350 }
351
352 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
353 address addr0 = addr;
354 if (addr0 == nullptr || dest->allocates2(addr0)) return;
355 CodeBuffer* cb = dest->outer();
356 addr = new_addr_for(addr0, cb, cb);
357 assert(allow_other_sections || dest->contains2(addr),
358 "addr must be in required section");
359 }
360
361
362 void CallRelocation::set_destination(address x) {
363 pd_set_call_destination(x);
364 }
365
366 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
367 // Usually a self-relative reference to an external routine.
368 // On some platforms, the reference is absolute (not self-relative).
369 // The enhanced use of pd_call_destination sorts this all out.
370 address orig_addr = old_addr_for(addr(), src, dest);
371 address callee = pd_call_destination(orig_addr);
372 // Reassert the callee address, this time in the new copy of the code.
373 pd_set_call_destination(callee);
374 }
375
376
377 //// pack/unpack methods
378
379 void oop_Relocation::pack_data_to(CodeSection* dest) {
380 short* p = (short*) dest->locs_end();
381 p = pack_1_int_to(p, _oop_index);
382 dest->set_locs_end((relocInfo*) p);
383 }
384
385
386 void oop_Relocation::unpack_data() {
387 _oop_index = unpack_1_int();
388 }
389
390 void metadata_Relocation::pack_data_to(CodeSection* dest) {
391 short* p = (short*) dest->locs_end();
392 p = pack_1_int_to(p, _metadata_index);
393 dest->set_locs_end((relocInfo*) p);
394 }
395
396
397 void metadata_Relocation::unpack_data() {
398 _metadata_index = unpack_1_int();
399 }
400
401
402 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
403 short* p = (short*) dest->locs_end();
404 address point = dest->locs_point();
405
406 normalize_address(_cached_value, dest);
407 jint x0 = scaled_offset_null_special(_cached_value, point);
408 p = pack_2_ints_to(p, x0, _method_index);
409 dest->set_locs_end((relocInfo*) p);
410 }
411
412
413 void virtual_call_Relocation::unpack_data() {
414 jint x0 = 0;
415 unpack_2_ints(x0, _method_index);
416 address point = addr();
417 _cached_value = x0==0? nullptr: address_from_scaled_offset(x0, point);
418 }
419
420 void runtime_call_w_cp_Relocation::pack_data_to(CodeSection * dest) {
421 short* p = pack_1_int_to((short *)dest->locs_end(), (jint)(_offset >> 2));
422 dest->set_locs_end((relocInfo*) p);
423 }
424
425 void runtime_call_w_cp_Relocation::unpack_data() {
426 _offset = unpack_1_int() << 2;
427 }
428
429 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
430 short* p = (short*) dest->locs_end();
431 CodeSection* insts = dest->outer()->insts();
432 normalize_address(_static_call, insts);
433 p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
434 dest->set_locs_end((relocInfo*) p);
435 }
436
437 void static_stub_Relocation::unpack_data() {
438 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
439 jint offset = unpack_1_int();
440 _static_call = address_from_scaled_offset(offset, base);
441 }
442
443 void trampoline_stub_Relocation::pack_data_to(CodeSection* dest ) {
444 short* p = (short*) dest->locs_end();
445 CodeSection* insts = dest->outer()->insts();
446 normalize_address(_owner, insts);
447 p = pack_1_int_to(p, scaled_offset(_owner, insts->start()));
448 dest->set_locs_end((relocInfo*) p);
449 }
450
451 void trampoline_stub_Relocation::unpack_data() {
452 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
453 _owner = address_from_scaled_offset(unpack_1_int(), base);
454 }
455
456 void external_word_Relocation::pack_data_to(CodeSection* dest) {
457 short* p = (short*) dest->locs_end();
458 #ifndef _LP64
459 p = pack_1_int_to(p, (int32_t) (intptr_t)_target);
460 #else
461 jlong t = (jlong) _target;
462 int32_t lo = low(t);
463 int32_t hi = high(t);
464 p = pack_2_ints_to(p, lo, hi);
465 #endif /* _LP64 */
466 dest->set_locs_end((relocInfo*) p);
467 }
468
469
470 void external_word_Relocation::unpack_data() {
471 #ifndef _LP64
472 _target = (address) (intptr_t)unpack_1_int();
473 #else
474 jint lo, hi;
475 unpack_2_ints(lo, hi);
476 jlong t = jlong_from(hi, lo);;
477 _target = (address) t;
478 #endif /* _LP64 */
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 postcond(src->section_index_of(target()) == CodeBuffer::SECT_NONE);
745 postcond(dest->section_index_of(target()) == CodeBuffer::SECT_NONE);
746 }
747
748
749 address external_word_Relocation::target() {
750 address target = _target;
751 if (target == nullptr) {
752 target = pd_get_address_from_code();
753 }
754 return target;
755 }
756
757
758 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
759 address target = _target;
760 if (target == nullptr) {
761 target = new_addr_for(this->target(), src, dest);
762 }
763 set_value(target);
764 }
765
766
767 address internal_word_Relocation::target() {
768 address target = _target;
769 if (target == nullptr) {
770 if (addr_in_const()) {
771 target = *(address*)addr();
772 } else {
773 target = pd_get_address_from_code();
774 }
775 }
776 return target;
777 }
778
779 //---------------------------------------------------------------------------------
780 // Non-product code
781
782 #ifndef PRODUCT
783
784 static const char* reloc_type_string(relocInfo::relocType t) {
785 switch (t) {
786 #define EACH_CASE(name) \
787 case relocInfo::name##_type: \
788 return #name;
789
790 APPLY_TO_RELOCATIONS(EACH_CASE);
791 #undef EACH_CASE
792
793 case relocInfo::none:
794 return "none";
795 case relocInfo::data_prefix_tag:
796 return "prefix";
797 default:
798 return "UNKNOWN RELOC TYPE";
799 }
800 }
801
802
803 void RelocIterator::print_current() {
804 if (!has_current()) {
805 tty->print_cr("(no relocs)");
806 return;
807 }
808 tty->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
809 p2i(_current), type(), reloc_type_string((relocInfo::relocType) type()), p2i(_addr), _current->addr_offset());
810 if (current()->format() != 0)
811 tty->print(" format=%d", current()->format());
812 if (datalen() == 1) {
813 tty->print(" data=%d", data()[0]);
814 } else if (datalen() > 0) {
815 tty->print(" data={");
816 for (int i = 0; i < datalen(); i++) {
817 tty->print("%04x", data()[i] & 0xFFFF);
818 }
819 tty->print("}");
820 }
821 tty->print("]");
822 switch (type()) {
823 case relocInfo::oop_type:
824 {
825 oop_Relocation* r = oop_reloc();
826 oop* oop_addr = nullptr;
827 oop raw_oop = nullptr;
828 oop oop_value = nullptr;
829 if (code() != nullptr || r->oop_is_immediate()) {
830 oop_addr = r->oop_addr();
831 raw_oop = *oop_addr;
832 oop_value = r->oop_value();
833 }
834 tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT "]",
835 p2i(oop_addr), p2i(raw_oop));
836 // Do not print the oop by default--we want this routine to
837 // work even during GC or other inconvenient times.
838 if (WizardMode && oop_value != nullptr) {
839 tty->print("oop_value=" INTPTR_FORMAT ": ", p2i(oop_value));
840 if (oopDesc::is_oop(oop_value)) {
841 oop_value->print_value_on(tty);
842 }
843 }
844 break;
845 }
846 case relocInfo::metadata_type:
847 {
848 metadata_Relocation* r = metadata_reloc();
849 Metadata** metadata_addr = nullptr;
850 Metadata* raw_metadata = nullptr;
851 Metadata* metadata_value = nullptr;
852 if (code() != nullptr || r->metadata_is_immediate()) {
853 metadata_addr = r->metadata_addr();
854 raw_metadata = *metadata_addr;
855 metadata_value = r->metadata_value();
856 }
857 tty->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT "]",
858 p2i(metadata_addr), p2i(raw_metadata));
859 if (metadata_value != nullptr) {
860 tty->print("metadata_value=" INTPTR_FORMAT ": ", p2i(metadata_value));
861 metadata_value->print_value_on(tty);
862 }
863 break;
864 }
865 case relocInfo::external_word_type:
866 case relocInfo::internal_word_type:
867 case relocInfo::section_word_type:
868 {
869 DataRelocation* r = (DataRelocation*) reloc();
870 tty->print(" | [target=" INTPTR_FORMAT "]", p2i(r->value())); //value==target
871 break;
872 }
873 case relocInfo::static_call_type:
874 {
875 static_call_Relocation* r = (static_call_Relocation*) reloc();
876 tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
877 p2i(r->destination()), p2i(r->method_value()));
878 break;
879 }
880 case relocInfo::runtime_call_type:
881 case relocInfo::runtime_call_w_cp_type:
882 {
883 CallRelocation* r = (CallRelocation*) reloc();
884 tty->print(" | [destination=" INTPTR_FORMAT "]", p2i(r->destination()));
885 break;
886 }
887 case relocInfo::virtual_call_type:
888 {
889 virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
890 tty->print(" | [destination=" INTPTR_FORMAT " cached_value=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
891 p2i(r->destination()), p2i(r->cached_value()), p2i(r->method_value()));
892 break;
893 }
894 case relocInfo::static_stub_type:
895 {
896 static_stub_Relocation* r = (static_stub_Relocation*) reloc();
897 tty->print(" | [static_call=" INTPTR_FORMAT "]", p2i(r->static_call()));
898 break;
899 }
900 case relocInfo::trampoline_stub_type:
901 {
902 trampoline_stub_Relocation* r = (trampoline_stub_Relocation*) reloc();
903 tty->print(" | [trampoline owner=" INTPTR_FORMAT "]", p2i(r->owner()));
904 break;
905 }
906 case relocInfo::opt_virtual_call_type:
907 {
908 opt_virtual_call_Relocation* r = (opt_virtual_call_Relocation*) reloc();
909 tty->print(" | [destination=" INTPTR_FORMAT " metadata=" INTPTR_FORMAT "]",
910 p2i(r->destination()), p2i(r->method_value()));
911 break;
912 }
913 default:
914 break;
915 }
916 tty->cr();
917 }
918
919
920 void RelocIterator::print() {
921 RelocIterator save_this = (*this);
922 relocInfo* scan = _current;
923 if (!has_current()) scan += 1; // nothing to scan here!
924
925 bool skip_next = has_current();
926 bool got_next;
927 while (true) {
928 got_next = (skip_next || next());
929 skip_next = false;
930
931 tty->print(" @" INTPTR_FORMAT ": ", p2i(scan));
932 relocInfo* newscan = _current+1;
933 if (!has_current()) newscan -= 1; // nothing to scan here!
934 while (scan < newscan) {
935 tty->print("%04x", *(short*)scan & 0xFFFF);
936 scan++;
937 }
938 tty->cr();
939
940 if (!got_next) break;
941 print_current();
942 }
943
944 (*this) = save_this;
945 }
946
947 // For the debugger:
948 extern "C"
949 void print_blob_locs(nmethod* nm) {
950 nm->print();
951 RelocIterator iter(nm);
952 iter.print();
953 }
954 extern "C"
955 void print_buf_locs(CodeBuffer* cb) {
956 FlagSetting fs(PrintRelocations, true);
957 cb->print();
958 }
959 #endif // !PRODUCT