1 /*
   2  * Copyright (c) 1997, 2014, 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 "runtime/stubCodeGenerator.hpp"
  32 #include "utilities/copy.hpp"
  33 
  34 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  35 
  36 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
  37 
  38 
  39 // Implementation of relocInfo
  40 
  41 #ifdef ASSERT
  42 relocInfo::relocInfo(relocType t, int off, int f) {
  43   assert(t != data_prefix_tag, "cannot build a prefix this way");
  44   assert((t & type_mask) == t, "wrong type");
  45   assert((f & format_mask) == f, "wrong format");
  46   assert(off >= 0 && off < offset_limit(), "offset out off bounds");
  47   assert((off & (offset_unit-1)) == 0, "misaligned offset");
  48   (*this) = relocInfo(t, RAW_BITS, off, f);
  49 }
  50 #endif
  51 
  52 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
  53   relocInfo* data = this+1;  // here's where the data might go
  54   dest->set_locs_end(data);  // sync end: the next call may read dest.locs_end
  55   reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
  56   relocInfo* data_limit = dest->locs_end();
  57   if (data_limit > data) {
  58     relocInfo suffix = (*this);
  59     data_limit = this->finish_prefix((short*) data_limit);
  60     // Finish up with the suffix.  (Hack note: pack_data_to might edit this.)
  61     *data_limit = suffix;
  62     dest->set_locs_end(data_limit+1);
  63   }
  64 }
  65 
  66 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
  67   assert(sizeof(relocInfo) == sizeof(short), "change this code");
  68   short* p = (short*)(this+1);
  69   assert(prefix_limit >= p, "must be a valid span of data");
  70   int plen = prefix_limit - p;
  71   if (plen == 0) {
  72     debug_only(_value = 0xFFFF);
  73     return this;                         // no data: remove self completely
  74   }
  75   if (plen == 1 && fits_into_immediate(p[0])) {
  76     (*this) = immediate_relocInfo(p[0]); // move data inside self
  77     return this+1;
  78   }
  79   // cannot compact, so just update the count and return the limit pointer
  80   (*this) = prefix_relocInfo(plen);   // write new datalen
  81   assert(data() + datalen() == prefix_limit, "pointers must line up");
  82   return (relocInfo*)prefix_limit;
  83 }
  84 
  85 
  86 void relocInfo::set_type(relocType t) {
  87   int old_offset = addr_offset();
  88   int old_format = format();
  89   (*this) = relocInfo(t, old_offset, old_format);
  90   assert(type()==(int)t, "sanity check");
  91   assert(addr_offset()==old_offset, "sanity check");
  92   assert(format()==old_format, "sanity check");
  93 }
  94 
  95 
  96 void relocInfo::set_format(int f) {
  97   int old_offset = addr_offset();
  98   assert((f & format_mask) == f, "wrong format");
  99   _value = (_value & ~(format_mask << offset_width)) | (f << offset_width);
 100   assert(addr_offset()==old_offset, "sanity check");
 101 }
 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 void relocInfo::remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type) {
 118   change_reloc_info_for_address(itr, pc, old_type, none);
 119 }
 120 
 121 
 122 // ----------------------------------------------------------------------------------------------------
 123 // Implementation of RelocIterator
 124 
 125 void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
 126   initialize_misc();
 127 
 128   if (nm == NULL && begin != NULL) {
 129     // allow nmethod to be deduced from beginning address
 130     CodeBlob* cb = CodeCache::find_blob(begin);
 131     nm = (cb != NULL) ? cb->as_nmethod_or_null() : NULL;
 132   }
 133   guarantee(nm != NULL, "must be able to deduce nmethod from other arguments");
 134 
 135   _code    = nm;
 136   _current = nm->relocation_begin() - 1;
 137   _end     = nm->relocation_end();
 138   _addr    = nm->content_begin();
 139 
 140   // Initialize code sections.
 141   _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
 142   _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
 143   _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin()  ;
 144 
 145   _section_end  [CodeBuffer::SECT_CONSTS] = nm->consts_end()  ;
 146   _section_end  [CodeBuffer::SECT_INSTS ] = nm->insts_end()   ;
 147   _section_end  [CodeBuffer::SECT_STUBS ] = nm->stub_end()    ;
 148 
 149   assert(!has_current(), "just checking");
 150   assert(begin == NULL || begin >= nm->code_begin(), "in bounds");
 151   assert(limit == NULL || limit <= nm->code_end(),   "in bounds");
 152   set_limits(begin, limit);
 153 }
 154 
 155 
 156 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
 157   initialize_misc();
 158 
 159   _current = cs->locs_start()-1;
 160   _end     = cs->locs_end();
 161   _addr    = cs->start();
 162   _code    = NULL; // Not cb->blob();
 163 
 164   CodeBuffer* cb = cs->outer();
 165   assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
 166   for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
 167     CodeSection* cs = cb->code_section(n);
 168     _section_start[n] = cs->start();
 169     _section_end  [n] = cs->end();
 170   }
 171 
 172   assert(!has_current(), "just checking");
 173 
 174   assert(begin == NULL || begin >= cs->start(), "in bounds");
 175   assert(limit == NULL || limit <= cs->end(),   "in bounds");
 176   set_limits(begin, limit);
 177 }
 178 
 179 
 180 enum { indexCardSize = 128 };
 181 struct RelocIndexEntry {
 182   jint addr_offset;          // offset from header_end of an addr()
 183   jint reloc_offset;         // offset from header_end of a relocInfo (prefix)
 184 };
 185 
 186 
 187 bool RelocIterator::addr_in_const() const {
 188   const int n = CodeBuffer::SECT_CONSTS;
 189   return section_start(n) <= addr() && addr() < section_end(n);
 190 }
 191 
 192 
 193 static inline int num_cards(int code_size) {
 194   return (code_size-1) / indexCardSize;
 195 }
 196 
 197 
 198 int RelocIterator::locs_and_index_size(int code_size, int locs_size) {
 199   if (!UseRelocIndex)  return locs_size;   // no index
 200   code_size = round_to(code_size, oopSize);
 201   locs_size = round_to(locs_size, oopSize);
 202   int index_size = num_cards(code_size) * sizeof(RelocIndexEntry);
 203   // format of indexed relocs:
 204   //   relocation_begin:   relocInfo ...
 205   //   index:              (addr,reloc#) ...
 206   //                       indexSize           :relocation_end
 207   return locs_size + index_size + BytesPerInt;
 208 }
 209 
 210 
 211 void RelocIterator::create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end) {
 212   address relocation_begin = (address)dest_begin;
 213   address relocation_end   = (address)dest_end;
 214   int     total_size       = relocation_end - relocation_begin;
 215   int     locs_size        = dest_count * sizeof(relocInfo);
 216   if (!UseRelocIndex) {
 217     Copy::fill_to_bytes(relocation_begin + locs_size, total_size-locs_size, 0);
 218     return;
 219   }
 220   int     index_size       = total_size - locs_size - BytesPerInt;      // find out how much space is left
 221   int     ncards           = index_size / sizeof(RelocIndexEntry);
 222   assert(total_size == locs_size + index_size + BytesPerInt, "checkin'");
 223   assert(index_size >= 0 && index_size % sizeof(RelocIndexEntry) == 0, "checkin'");
 224   jint*   index_size_addr  = (jint*)relocation_end - 1;
 225 
 226   assert(sizeof(jint) == BytesPerInt, "change this code");
 227 
 228   *index_size_addr = index_size;
 229   if (index_size != 0) {
 230     assert(index_size > 0, "checkin'");
 231 
 232     RelocIndexEntry* index = (RelocIndexEntry *)(relocation_begin + locs_size);
 233     assert(index == (RelocIndexEntry*)index_size_addr - ncards, "checkin'");
 234 
 235     // walk over the relocations, and fill in index entries as we go
 236     RelocIterator iter;
 237     const address    initial_addr    = NULL;
 238     relocInfo* const initial_current = dest_begin - 1;  // biased by -1 like elsewhere
 239 
 240     iter._code    = NULL;
 241     iter._addr    = initial_addr;
 242     iter._limit   = (address)(intptr_t)(ncards * indexCardSize);
 243     iter._current = initial_current;
 244     iter._end     = dest_begin + dest_count;
 245 
 246     int i = 0;
 247     address next_card_addr = (address)indexCardSize;
 248     int addr_offset = 0;
 249     int reloc_offset = 0;
 250     while (true) {
 251       // Checkpoint the iterator before advancing it.
 252       addr_offset  = iter._addr    - initial_addr;
 253       reloc_offset = iter._current - initial_current;
 254       if (!iter.next())  break;
 255       while (iter.addr() >= next_card_addr) {
 256         index[i].addr_offset  = addr_offset;
 257         index[i].reloc_offset = reloc_offset;
 258         i++;
 259         next_card_addr += indexCardSize;
 260       }
 261     }
 262     while (i < ncards) {
 263       index[i].addr_offset  = addr_offset;
 264       index[i].reloc_offset = reloc_offset;
 265       i++;
 266     }
 267   }
 268 }
 269 
 270 
 271 void RelocIterator::set_limits(address begin, address limit) {
 272   int index_size = 0;
 273   if (UseRelocIndex && _code != NULL) {
 274     index_size = ((jint*)_end)[-1];
 275     _end = (relocInfo*)( (address)_end - index_size - BytesPerInt );
 276   }
 277 
 278   _limit = limit;
 279 
 280   // the limit affects this next stuff:
 281   if (begin != NULL) {
 282 #ifdef ASSERT
 283     // In ASSERT mode we do not actually use the index, but simply
 284     // check that its contents would have led us to the right answer.
 285     address addrCheck = _addr;
 286     relocInfo* infoCheck = _current;
 287 #endif // ASSERT
 288     if (index_size > 0) {
 289       // skip ahead
 290       RelocIndexEntry* index       = (RelocIndexEntry*)_end;
 291       RelocIndexEntry* index_limit = (RelocIndexEntry*)((address)index + index_size);
 292       assert(_addr == _code->code_begin(), "_addr must be unadjusted");
 293       int card = (begin - _addr) / indexCardSize;
 294       if (card > 0) {
 295         if (index+card-1 < index_limit)  index += card-1;
 296         else                             index = index_limit - 1;
 297 #ifdef ASSERT
 298         addrCheck = _addr    + index->addr_offset;
 299         infoCheck = _current + index->reloc_offset;
 300 #else
 301         // Advance the iterator immediately to the last valid state
 302         // for the previous card.  Calling "next" will then advance
 303         // it to the first item on the required card.
 304         _addr    += index->addr_offset;
 305         _current += index->reloc_offset;
 306 #endif // ASSERT
 307       }
 308     }
 309 
 310     relocInfo* backup;
 311     address    backup_addr;
 312     while (true) {
 313       backup      = _current;
 314       backup_addr = _addr;
 315 #ifdef ASSERT
 316       if (backup == infoCheck) {
 317         assert(backup_addr == addrCheck, "must match"); addrCheck = NULL; infoCheck = NULL;
 318       } else {
 319         assert(addrCheck == NULL || backup_addr <= addrCheck, "must not pass addrCheck");
 320       }
 321 #endif // ASSERT
 322       if (!next() || addr() >= begin) break;
 323     }
 324     assert(addrCheck == NULL || addrCheck == backup_addr, "must have matched addrCheck");
 325     assert(infoCheck == NULL || infoCheck == backup,      "must have matched infoCheck");
 326     // At this point, either we are at the first matching record,
 327     // or else there is no such record, and !has_current().
 328     // In either case, revert to the immediatly preceding state.
 329     _current = backup;
 330     _addr    = backup_addr;
 331     set_has_current(false);
 332   }
 333 }
 334 
 335 
 336 void RelocIterator::set_limit(address limit) {
 337   address code_end = (address)code() + code()->size();
 338   assert(limit == NULL || limit <= code_end, "in bounds");
 339   _limit = limit;
 340 }
 341 
 342 // All the strange bit-encodings are in here.
 343 // The idea is to encode relocation data which are small integers
 344 // very efficiently (a single extra halfword).  Larger chunks of
 345 // relocation data need a halfword header to hold their size.
 346 void RelocIterator::advance_over_prefix() {
 347   if (_current->is_datalen()) {
 348     _data    = (short*) _current->data();
 349     _datalen =          _current->datalen();
 350     _current += _datalen + 1;   // skip the embedded data & header
 351   } else {
 352     _databuf = _current->immediate();
 353     _data = &_databuf;
 354     _datalen = 1;
 355     _current++;                 // skip the header
 356   }
 357   // The client will see the following relocInfo, whatever that is.
 358   // It is the reloc to which the preceding data applies.
 359 }
 360 
 361 
 362 void RelocIterator::initialize_misc() {
 363   set_has_current(false);
 364   for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
 365     _section_start[i] = NULL;  // these will be lazily computed, if needed
 366     _section_end  [i] = NULL;
 367   }
 368 }
 369 
 370 
 371 Relocation* RelocIterator::reloc() {
 372   // (take the "switch" out-of-line)
 373   relocInfo::relocType t = type();
 374   if (false) {}
 375   #define EACH_TYPE(name)                             \
 376   else if (t == relocInfo::name##_type) {             \
 377     return name##_reloc();                            \
 378   }
 379   APPLY_TO_RELOCATIONS(EACH_TYPE);
 380   #undef EACH_TYPE
 381   assert(t == relocInfo::none, "must be padding");
 382   return new(_rh) Relocation();
 383 }
 384 
 385 
 386 //////// Methods for flyweight Relocation types
 387 
 388 
 389 RelocationHolder RelocationHolder::plus(int offset) const {
 390   if (offset != 0) {
 391     switch (type()) {
 392     case relocInfo::none:
 393       break;
 394     case relocInfo::oop_type:
 395       {
 396         oop_Relocation* r = (oop_Relocation*)reloc();
 397         return oop_Relocation::spec(r->oop_index(), r->offset() + offset);
 398       }
 399     case relocInfo::metadata_type:
 400       {
 401         metadata_Relocation* r = (metadata_Relocation*)reloc();
 402         return metadata_Relocation::spec(r->metadata_index(), r->offset() + offset);
 403       }
 404     default:
 405       ShouldNotReachHere();
 406     }
 407   }
 408   return (*this);
 409 }
 410 
 411 
 412 void Relocation::guarantee_size() {
 413   guarantee(false, "Make _relocbuf bigger!");
 414 }
 415 
 416     // some relocations can compute their own values
 417 address Relocation::value() {
 418   ShouldNotReachHere();
 419   return NULL;
 420 }
 421 
 422 
 423 void Relocation::set_value(address x) {
 424   ShouldNotReachHere();
 425 }
 426 
 427 
 428 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
 429   if (rtype == relocInfo::none)  return RelocationHolder::none;
 430   relocInfo ri = relocInfo(rtype, 0);
 431   RelocIterator itr;
 432   itr.set_current(ri);
 433   itr.reloc();
 434   return itr._rh;
 435 }
 436 
 437 int32_t Relocation::runtime_address_to_index(address runtime_address) {
 438   assert(!is_reloc_index((intptr_t)runtime_address), "must not look like an index");
 439 
 440   if (runtime_address == NULL)  return 0;
 441 
 442   StubCodeDesc* p = StubCodeDesc::desc_for(runtime_address);
 443   if (p != NULL && p->begin() == runtime_address) {
 444     assert(is_reloc_index(p->index()), "there must not be too many stubs");
 445     return (int32_t)p->index();
 446   } else {
 447     // Known "miscellaneous" non-stub pointers:
 448     // os::get_polling_page(), SafepointSynchronize::address_of_state()
 449     if (PrintRelocations) {
 450       tty->print_cr("random unregistered address in relocInfo: " INTPTR_FORMAT, runtime_address);
 451     }
 452 #ifndef _LP64
 453     return (int32_t) (intptr_t)runtime_address;
 454 #else
 455     // didn't fit return non-index
 456     return -1;
 457 #endif /* _LP64 */
 458   }
 459 }
 460 
 461 
 462 address Relocation::index_to_runtime_address(int32_t index) {
 463   if (index == 0)  return NULL;
 464 
 465   if (is_reloc_index(index)) {
 466     StubCodeDesc* p = StubCodeDesc::desc_for_index(index);
 467     assert(p != NULL, "there must be a stub for this index");
 468     return p->begin();
 469   } else {
 470 #ifndef _LP64
 471     // this only works on 32bit machines
 472     return (address) ((intptr_t) index);
 473 #else
 474     fatal("Relocation::index_to_runtime_address, int32_t not pointer sized");
 475     return NULL;
 476 #endif /* _LP64 */
 477   }
 478 }
 479 
 480 address Relocation::old_addr_for(address newa,
 481                                  const CodeBuffer* src, CodeBuffer* dest) {
 482   int sect = dest->section_index_of(newa);
 483   guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
 484   address ostart = src->code_section(sect)->start();
 485   address nstart = dest->code_section(sect)->start();
 486   return ostart + (newa - nstart);
 487 }
 488 
 489 address Relocation::new_addr_for(address olda,
 490                                  const CodeBuffer* src, CodeBuffer* dest) {
 491   debug_only(const CodeBuffer* src0 = src);
 492   int sect = CodeBuffer::SECT_NONE;
 493   // Look for olda in the source buffer, and all previous incarnations
 494   // if the source buffer has been expanded.
 495   for (; src != NULL; src = src->before_expand()) {
 496     sect = src->section_index_of(olda);
 497     if (sect != CodeBuffer::SECT_NONE)  break;
 498   }
 499   guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
 500   address ostart = src->code_section(sect)->start();
 501   address nstart = dest->code_section(sect)->start();
 502   return nstart + (olda - ostart);
 503 }
 504 
 505 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
 506   address addr0 = addr;
 507   if (addr0 == NULL || dest->allocates2(addr0))  return;
 508   CodeBuffer* cb = dest->outer();
 509   addr = new_addr_for(addr0, cb, cb);
 510   assert(allow_other_sections || dest->contains2(addr),
 511          "addr must be in required section");
 512 }
 513 
 514 
 515 void CallRelocation::set_destination(address x) {
 516   pd_set_call_destination(x);
 517 }
 518 
 519 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 520   // Usually a self-relative reference to an external routine.
 521   // On some platforms, the reference is absolute (not self-relative).
 522   // The enhanced use of pd_call_destination sorts this all out.
 523   address orig_addr = old_addr_for(addr(), src, dest);
 524   address callee    = pd_call_destination(orig_addr);
 525   // Reassert the callee address, this time in the new copy of the code.
 526   pd_set_call_destination(callee);
 527 }
 528 
 529 
 530 //// pack/unpack methods
 531 
 532 void oop_Relocation::pack_data_to(CodeSection* dest) {
 533   short* p = (short*) dest->locs_end();
 534   p = pack_2_ints_to(p, _oop_index, _offset);
 535   dest->set_locs_end((relocInfo*) p);
 536 }
 537 
 538 
 539 void oop_Relocation::unpack_data() {
 540   unpack_2_ints(_oop_index, _offset);
 541 }
 542 
 543 void metadata_Relocation::pack_data_to(CodeSection* dest) {
 544   short* p = (short*) dest->locs_end();
 545   p = pack_2_ints_to(p, _metadata_index, _offset);
 546   dest->set_locs_end((relocInfo*) p);
 547 }
 548 
 549 
 550 void metadata_Relocation::unpack_data() {
 551   unpack_2_ints(_metadata_index, _offset);
 552 }
 553 
 554 
 555 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
 556   short*  p     = (short*) dest->locs_end();
 557   address point =          dest->locs_point();
 558 
 559   normalize_address(_cached_value, dest);
 560   jint x0 = scaled_offset_null_special(_cached_value, point);
 561   p = pack_1_int_to(p, x0);
 562   dest->set_locs_end((relocInfo*) p);
 563 }
 564 
 565 
 566 void virtual_call_Relocation::unpack_data() {
 567   jint x0 = unpack_1_int();
 568   address point = addr();
 569   _cached_value = x0==0? NULL: address_from_scaled_offset(x0, point);
 570 }
 571 
 572 
 573 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
 574   short* p = (short*) dest->locs_end();
 575   CodeSection* insts = dest->outer()->insts();
 576   normalize_address(_static_call, insts);
 577   p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
 578   dest->set_locs_end((relocInfo*) p);
 579 }
 580 
 581 void static_stub_Relocation::unpack_data() {
 582   address base = binding()->section_start(CodeBuffer::SECT_INSTS);
 583   _static_call = address_from_scaled_offset(unpack_1_int(), base);
 584 }
 585 
 586 void trampoline_stub_Relocation::pack_data_to(CodeSection* dest ) {
 587   short* p = (short*) dest->locs_end();
 588   CodeSection* insts = dest->outer()->insts();
 589   normalize_address(_owner, insts);
 590   p = pack_1_int_to(p, scaled_offset(_owner, insts->start()));
 591   dest->set_locs_end((relocInfo*) p);
 592 }
 593 
 594 void trampoline_stub_Relocation::unpack_data() {
 595   address base = binding()->section_start(CodeBuffer::SECT_INSTS);
 596   _owner = address_from_scaled_offset(unpack_1_int(), base);
 597 }
 598 
 599 void external_word_Relocation::pack_data_to(CodeSection* dest) {
 600   short* p = (short*) dest->locs_end();
 601   int32_t index = runtime_address_to_index(_target);
 602 #ifndef _LP64
 603   p = pack_1_int_to(p, index);
 604 #else
 605   if (is_reloc_index(index)) {
 606     p = pack_2_ints_to(p, index, 0);
 607   } else {
 608     jlong t = (jlong) _target;
 609     int32_t lo = low(t);
 610     int32_t hi = high(t);
 611     p = pack_2_ints_to(p, lo, hi);
 612     DEBUG_ONLY(jlong t1 = jlong_from(hi, lo));
 613     assert(!is_reloc_index(t1) && (address) t1 == _target, "not symmetric");
 614   }
 615 #endif /* _LP64 */
 616   dest->set_locs_end((relocInfo*) p);
 617 }
 618 
 619 
 620 void external_word_Relocation::unpack_data() {
 621 #ifndef _LP64
 622   _target = index_to_runtime_address(unpack_1_int());
 623 #else
 624   int32_t lo, hi;
 625   unpack_2_ints(lo, hi);
 626   jlong t = jlong_from(hi, lo);;
 627   if (is_reloc_index(t)) {
 628     _target = index_to_runtime_address(t);
 629   } else {
 630     _target = (address) t;
 631   }
 632 #endif /* _LP64 */
 633 }
 634 
 635 
 636 void internal_word_Relocation::pack_data_to(CodeSection* dest) {
 637   short* p = (short*) dest->locs_end();
 638   normalize_address(_target, dest, true);
 639 
 640   // Check whether my target address is valid within this section.
 641   // If not, strengthen the relocation type to point to another section.
 642   int sindex = _section;
 643   if (sindex == CodeBuffer::SECT_NONE && _target != NULL
 644       && (!dest->allocates(_target) || _target == dest->locs_point())) {
 645     sindex = dest->outer()->section_index_of(_target);
 646     guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
 647     relocInfo* base = dest->locs_end() - 1;
 648     assert(base->type() == this->type(), "sanity");
 649     // Change the written type, to be section_word_type instead.
 650     base->set_type(relocInfo::section_word_type);
 651   }
 652 
 653   // Note: An internal_word relocation cannot refer to its own instruction,
 654   // because we reserve "0" to mean that the pointer itself is embedded
 655   // in the code stream.  We use a section_word relocation for such cases.
 656 
 657   if (sindex == CodeBuffer::SECT_NONE) {
 658     assert(type() == relocInfo::internal_word_type, "must be base class");
 659     guarantee(_target == NULL || dest->allocates2(_target), "must be within the given code section");
 660     jint x0 = scaled_offset_null_special(_target, dest->locs_point());
 661     assert(!(x0 == 0 && _target != NULL), "correct encoding of null target");
 662     p = pack_1_int_to(p, x0);
 663   } else {
 664     assert(_target != NULL, "sanity");
 665     CodeSection* sect = dest->outer()->code_section(sindex);
 666     guarantee(sect->allocates2(_target), "must be in correct section");
 667     address base = sect->start();
 668     jint offset = scaled_offset(_target, base);
 669     assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
 670     assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
 671     p = pack_1_int_to(p, (offset << section_width) | sindex);
 672   }
 673 
 674   dest->set_locs_end((relocInfo*) p);
 675 }
 676 
 677 
 678 void internal_word_Relocation::unpack_data() {
 679   jint x0 = unpack_1_int();
 680   _target = x0==0? NULL: address_from_scaled_offset(x0, addr());
 681   _section = CodeBuffer::SECT_NONE;
 682 }
 683 
 684 
 685 void section_word_Relocation::unpack_data() {
 686   jint    x      = unpack_1_int();
 687   jint    offset = (x >> section_width);
 688   int     sindex = (x & ((1<<section_width)-1));
 689   address base   = binding()->section_start(sindex);
 690 
 691   _section = sindex;
 692   _target  = address_from_scaled_offset(offset, base);
 693 }
 694 
 695 //// miscellaneous methods
 696 oop* oop_Relocation::oop_addr() {
 697   int n = _oop_index;
 698   if (n == 0) {
 699     // oop is stored in the code stream
 700     return (oop*) pd_address_in_code();
 701   } else {
 702     // oop is stored in table at nmethod::oops_begin
 703     return code()->oop_addr_at(n);
 704   }
 705 }
 706 
 707 
 708 oop oop_Relocation::oop_value() {
 709   oop v = *oop_addr();
 710   // clean inline caches store a special pseudo-null
 711   if (v == Universe::non_oop_word())  v = NULL;
 712   return v;
 713 }
 714 
 715 
 716 void oop_Relocation::fix_oop_relocation() {
 717   if (!oop_is_immediate()) {
 718     // get the oop from the pool, and re-insert it into the instruction:
 719     set_value(value());
 720   }
 721 }
 722 
 723 
 724 void oop_Relocation::verify_oop_relocation() {
 725   if (!oop_is_immediate()) {
 726     // get the oop from the pool, and re-insert it into the instruction:
 727     verify_value(value());
 728   }
 729 }
 730 
 731 // meta data versions
 732 Metadata** metadata_Relocation::metadata_addr() {
 733   int n = _metadata_index;
 734   if (n == 0) {
 735     // metadata is stored in the code stream
 736     return (Metadata**) pd_address_in_code();
 737     } else {
 738     // metadata is stored in table at nmethod::metadatas_begin
 739     return code()->metadata_addr_at(n);
 740     }
 741   }
 742 
 743 
 744 Metadata* metadata_Relocation::metadata_value() {
 745   Metadata* v = *metadata_addr();
 746   // clean inline caches store a special pseudo-null
 747   if (v == (Metadata*)Universe::non_oop_word())  v = NULL;
 748   return v;
 749   }
 750 
 751 
 752 void metadata_Relocation::fix_metadata_relocation() {
 753   if (!metadata_is_immediate()) {
 754     // get the metadata from the pool, and re-insert it into the instruction:
 755     pd_fix_value(value());
 756   }
 757 }
 758 
 759 
 760 void metadata_Relocation::verify_metadata_relocation() {
 761   if (!metadata_is_immediate()) {
 762     // get the metadata from the pool, and re-insert it into the instruction:
 763     verify_value(value());
 764   }
 765 }
 766 
 767 address virtual_call_Relocation::cached_value() {
 768   assert(_cached_value != NULL && _cached_value < addr(), "must precede ic_call");
 769   return _cached_value;
 770 }
 771 
 772 
 773 void virtual_call_Relocation::clear_inline_cache() {
 774   // No stubs for ICs
 775   // Clean IC
 776   ResourceMark rm;
 777   CompiledIC* icache = CompiledIC_at(this);
 778   icache->set_to_clean();
 779 }
 780 
 781 
 782 void opt_virtual_call_Relocation::clear_inline_cache() {
 783   // No stubs for ICs
 784   // Clean IC
 785   ResourceMark rm;
 786   CompiledIC* icache = CompiledIC_at(this);
 787   icache->set_to_clean();
 788 }
 789 
 790 
 791 address opt_virtual_call_Relocation::static_stub() {
 792   // search for the static stub who points back to this static call
 793   address static_call_addr = addr();
 794   RelocIterator iter(code());
 795   while (iter.next()) {
 796     if (iter.type() == relocInfo::static_stub_type) {
 797       if (iter.static_stub_reloc()->static_call() == static_call_addr) {
 798         return iter.addr();
 799       }
 800     }
 801   }
 802   return NULL;
 803 }
 804 
 805 
 806 void static_call_Relocation::clear_inline_cache() {
 807   // Safe call site info
 808   CompiledStaticCall* handler = compiledStaticCall_at(this);
 809   handler->set_to_clean();
 810 }
 811 
 812 
 813 address static_call_Relocation::static_stub() {
 814   // search for the static stub who points back to this static call
 815   address static_call_addr = addr();
 816   RelocIterator iter(code());
 817   while (iter.next()) {
 818     if (iter.type() == relocInfo::static_stub_type) {
 819       if (iter.static_stub_reloc()->static_call() == static_call_addr) {
 820         return iter.addr();
 821       }
 822     }
 823   }
 824   return NULL;
 825 }
 826 
 827 // Finds the trampoline address for a call. If no trampoline stub is
 828 // found NULL is returned which can be handled by the caller.
 829 address trampoline_stub_Relocation::get_trampoline_for(address call, nmethod* code) {
 830   // There are no relocations available when the code gets relocated
 831   // because of CodeBuffer expansion.
 832   if (code->relocation_size() == 0)
 833     return NULL;
 834 
 835   RelocIterator iter(code, call);
 836   while (iter.next()) {
 837     if (iter.type() == relocInfo::trampoline_stub_type) {
 838       if (iter.trampoline_stub_reloc()->owner() == call) {
 839         return iter.addr();
 840       }
 841     }
 842   }
 843 
 844   return NULL;
 845 }
 846 
 847 void static_stub_Relocation::clear_inline_cache() {
 848   // Call stub is only used when calling the interpreted code.
 849   // It does not really need to be cleared, except that we want to clean out the methodoop.
 850   CompiledStaticCall::set_stub_to_clean(this);
 851 }
 852 
 853 
 854 void external_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 855   address target = _target;
 856   if (target == NULL) {
 857     // An absolute embedded reference to an external location,
 858     // which means there is nothing to fix here.
 859     return;
 860   }
 861   // Probably this reference is absolute, not relative, so the
 862   // following is probably a no-op.
 863   assert(src->section_index_of(target) == CodeBuffer::SECT_NONE, "sanity");
 864   set_value(target);
 865 }
 866 
 867 
 868 address external_word_Relocation::target() {
 869   address target = _target;
 870   if (target == NULL) {
 871     target = pd_get_address_from_code();
 872   }
 873   return target;
 874 }
 875 
 876 
 877 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
 878   address target = _target;
 879   if (target == NULL) {
 880     target = new_addr_for(this->target(), src, dest);
 881   }
 882   set_value(target);
 883 }
 884 
 885 
 886 address internal_word_Relocation::target() {
 887   address target = _target;
 888   if (target == NULL) {
 889     if (addr_in_const()) {
 890       target = *(address*)addr();
 891     } else {
 892       target = pd_get_address_from_code();
 893     }
 894   }
 895   return target;
 896 }
 897 
 898 //---------------------------------------------------------------------------------
 899 // Non-product code
 900 
 901 #ifndef PRODUCT
 902 
 903 static const char* reloc_type_string(relocInfo::relocType t) {
 904   switch (t) {
 905   #define EACH_CASE(name) \
 906   case relocInfo::name##_type: \
 907     return #name;
 908 
 909   APPLY_TO_RELOCATIONS(EACH_CASE);
 910   #undef EACH_CASE
 911 
 912   case relocInfo::none:
 913     return "none";
 914   case relocInfo::data_prefix_tag:
 915     return "prefix";
 916   default:
 917     return "UNKNOWN RELOC TYPE";
 918   }
 919 }
 920 
 921 
 922 void RelocIterator::print_current() {
 923   if (!has_current()) {
 924     tty->print_cr("(no relocs)");
 925     return;
 926   }
 927   tty->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
 928              _current, type(), reloc_type_string((relocInfo::relocType) type()), _addr, _current->addr_offset());
 929   if (current()->format() != 0)
 930     tty->print(" format=%d", current()->format());
 931   if (datalen() == 1) {
 932     tty->print(" data=%d", data()[0]);
 933   } else if (datalen() > 0) {
 934     tty->print(" data={");
 935     for (int i = 0; i < datalen(); i++) {
 936       tty->print("%04x", data()[i] & 0xFFFF);
 937     }
 938     tty->print("}");
 939   }
 940   tty->print("]");
 941   switch (type()) {
 942   case relocInfo::oop_type:
 943     {
 944       oop_Relocation* r = oop_reloc();
 945       oop* oop_addr  = NULL;
 946       oop  raw_oop   = NULL;
 947       oop  oop_value = NULL;
 948       if (code() != NULL || r->oop_is_immediate()) {
 949         oop_addr  = r->oop_addr();
 950         raw_oop   = *oop_addr;
 951         oop_value = r->oop_value();
 952       }
 953       tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
 954                  oop_addr, (address)raw_oop, r->offset());
 955       // Do not print the oop by default--we want this routine to
 956       // work even during GC or other inconvenient times.
 957       if (WizardMode && oop_value != NULL) {
 958         tty->print("oop_value=" INTPTR_FORMAT ": ", (address)oop_value);
 959         oop_value->print_value_on(tty);
 960       }
 961       break;
 962     }
 963   case relocInfo::metadata_type:
 964     {
 965       metadata_Relocation* r = metadata_reloc();
 966       Metadata** metadata_addr  = NULL;
 967       Metadata*    raw_metadata   = NULL;
 968       Metadata*    metadata_value = NULL;
 969       if (code() != NULL || r->metadata_is_immediate()) {
 970         metadata_addr  = r->metadata_addr();
 971         raw_metadata   = *metadata_addr;
 972         metadata_value = r->metadata_value();
 973       }
 974       tty->print(" | [metadata_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
 975                  metadata_addr, (address)raw_metadata, r->offset());
 976       if (metadata_value != NULL) {
 977         tty->print("metadata_value=" INTPTR_FORMAT ": ", (address)metadata_value);
 978         metadata_value->print_value_on(tty);
 979       }
 980       break;
 981     }
 982   case relocInfo::external_word_type:
 983   case relocInfo::internal_word_type:
 984   case relocInfo::section_word_type:
 985     {
 986       DataRelocation* r = (DataRelocation*) reloc();
 987       tty->print(" | [target=" INTPTR_FORMAT "]", r->value()); //value==target
 988       break;
 989     }
 990   case relocInfo::static_call_type:
 991   case relocInfo::runtime_call_type:
 992     {
 993       CallRelocation* r = (CallRelocation*) reloc();
 994       tty->print(" | [destination=" INTPTR_FORMAT "]", r->destination());
 995       break;
 996     }
 997   case relocInfo::virtual_call_type:
 998     {
 999       virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
1000       tty->print(" | [destination=" INTPTR_FORMAT " cached_value=" INTPTR_FORMAT "]",
1001                  r->destination(), r->cached_value());
1002       break;
1003     }
1004   case relocInfo::static_stub_type:
1005     {
1006       static_stub_Relocation* r = (static_stub_Relocation*) reloc();
1007       tty->print(" | [static_call=" INTPTR_FORMAT "]", r->static_call());
1008       break;
1009     }
1010   case relocInfo::trampoline_stub_type:
1011     {
1012       trampoline_stub_Relocation* r = (trampoline_stub_Relocation*) reloc();
1013       tty->print(" | [trampoline owner=" INTPTR_FORMAT "]", r->owner());
1014       break;
1015     }
1016   }
1017   tty->cr();
1018 }
1019 
1020 
1021 void RelocIterator::print() {
1022   RelocIterator save_this = (*this);
1023   relocInfo* scan = _current;
1024   if (!has_current())  scan += 1;  // nothing to scan here!
1025 
1026   bool skip_next = has_current();
1027   bool got_next;
1028   while (true) {
1029     got_next = (skip_next || next());
1030     skip_next = false;
1031 
1032     tty->print("         @" INTPTR_FORMAT ": ", scan);
1033     relocInfo* newscan = _current+1;
1034     if (!has_current())  newscan -= 1;  // nothing to scan here!
1035     while (scan < newscan) {
1036       tty->print("%04x", *(short*)scan & 0xFFFF);
1037       scan++;
1038     }
1039     tty->cr();
1040 
1041     if (!got_next)  break;
1042     print_current();
1043   }
1044 
1045   (*this) = save_this;
1046 }
1047 
1048 // For the debugger:
1049 extern "C"
1050 void print_blob_locs(nmethod* nm) {
1051   nm->print();
1052   RelocIterator iter(nm);
1053   iter.print();
1054 }
1055 extern "C"
1056 void print_buf_locs(CodeBuffer* cb) {
1057   FlagSetting fs(PrintRelocations, true);
1058   cb->print();
1059 }
1060 #endif // !PRODUCT