Fri, 18 Mar 2011 15:52:42 -0700
7028374: race in fix_oop_relocations for scavengeable nmethods
Reviewed-by: kvn
1 /*
2 * Copyright (c) 1997, 2010, 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.
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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).
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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.
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23 */
25 #include "precompiled.hpp"
26 #include "code/compiledIC.hpp"
27 #include "code/nmethod.hpp"
28 #include "code/relocInfo.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "runtime/stubCodeGenerator.hpp"
31 #include "utilities/copy.hpp"
32 #ifdef TARGET_ARCH_x86
33 # include "assembler_x86.inline.hpp"
34 # include "nativeInst_x86.hpp"
35 #endif
36 #ifdef TARGET_ARCH_sparc
37 # include "assembler_sparc.inline.hpp"
38 # include "nativeInst_sparc.hpp"
39 #endif
40 #ifdef TARGET_ARCH_zero
41 # include "assembler_zero.inline.hpp"
42 # include "nativeInst_zero.hpp"
43 #endif
44 #ifdef TARGET_ARCH_arm
45 # include "assembler_arm.inline.hpp"
46 # include "nativeInst_arm.hpp"
47 #endif
48 #ifdef TARGET_ARCH_ppc
49 # include "assembler_ppc.inline.hpp"
50 # include "nativeInst_ppc.hpp"
51 #endif
54 const RelocationHolder RelocationHolder::none; // its type is relocInfo::none
57 // Implementation of relocInfo
59 #ifdef ASSERT
60 relocInfo::relocInfo(relocType t, int off, int f) {
61 assert(t != data_prefix_tag, "cannot build a prefix this way");
62 assert((t & type_mask) == t, "wrong type");
63 assert((f & format_mask) == f, "wrong format");
64 assert(off >= 0 && off < offset_limit(), "offset out off bounds");
65 assert((off & (offset_unit-1)) == 0, "misaligned offset");
66 (*this) = relocInfo(t, RAW_BITS, off, f);
67 }
68 #endif
70 void relocInfo::initialize(CodeSection* dest, Relocation* reloc) {
71 relocInfo* data = this+1; // here's where the data might go
72 dest->set_locs_end(data); // sync end: the next call may read dest.locs_end
73 reloc->pack_data_to(dest); // maybe write data into locs, advancing locs_end
74 relocInfo* data_limit = dest->locs_end();
75 if (data_limit > data) {
76 relocInfo suffix = (*this);
77 data_limit = this->finish_prefix((short*) data_limit);
78 // Finish up with the suffix. (Hack note: pack_data_to might edit this.)
79 *data_limit = suffix;
80 dest->set_locs_end(data_limit+1);
81 }
82 }
84 relocInfo* relocInfo::finish_prefix(short* prefix_limit) {
85 assert(sizeof(relocInfo) == sizeof(short), "change this code");
86 short* p = (short*)(this+1);
87 assert(prefix_limit >= p, "must be a valid span of data");
88 int plen = prefix_limit - p;
89 if (plen == 0) {
90 debug_only(_value = 0xFFFF);
91 return this; // no data: remove self completely
92 }
93 if (plen == 1 && fits_into_immediate(p[0])) {
94 (*this) = immediate_relocInfo(p[0]); // move data inside self
95 return this+1;
96 }
97 // cannot compact, so just update the count and return the limit pointer
98 (*this) = prefix_relocInfo(plen); // write new datalen
99 assert(data() + datalen() == prefix_limit, "pointers must line up");
100 return (relocInfo*)prefix_limit;
101 }
104 void relocInfo::set_type(relocType t) {
105 int old_offset = addr_offset();
106 int old_format = format();
107 (*this) = relocInfo(t, old_offset, old_format);
108 assert(type()==(int)t, "sanity check");
109 assert(addr_offset()==old_offset, "sanity check");
110 assert(format()==old_format, "sanity check");
111 }
114 void relocInfo::set_format(int f) {
115 int old_offset = addr_offset();
116 assert((f & format_mask) == f, "wrong format");
117 _value = (_value & ~(format_mask << offset_width)) | (f << offset_width);
118 assert(addr_offset()==old_offset, "sanity check");
119 }
122 void relocInfo::change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type) {
123 bool found = false;
124 while (itr->next() && !found) {
125 if (itr->addr() == pc) {
126 assert(itr->type()==old_type, "wrong relocInfo type found");
127 itr->current()->set_type(new_type);
128 found=true;
129 }
130 }
131 assert(found, "no relocInfo found for pc");
132 }
135 void relocInfo::remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type) {
136 change_reloc_info_for_address(itr, pc, old_type, none);
137 }
140 // ----------------------------------------------------------------------------------------------------
141 // Implementation of RelocIterator
143 void RelocIterator::initialize(nmethod* nm, address begin, address limit) {
144 initialize_misc();
146 if (nm == NULL && begin != NULL) {
147 // allow nmethod to be deduced from beginning address
148 CodeBlob* cb = CodeCache::find_blob(begin);
149 nm = cb->as_nmethod_or_null();
150 }
151 assert(nm != NULL, "must be able to deduce nmethod from other arguments");
153 _code = nm;
154 _current = nm->relocation_begin() - 1;
155 _end = nm->relocation_end();
156 _addr = nm->content_begin();
158 // Initialize code sections.
159 _section_start[CodeBuffer::SECT_CONSTS] = nm->consts_begin();
160 _section_start[CodeBuffer::SECT_INSTS ] = nm->insts_begin() ;
161 _section_start[CodeBuffer::SECT_STUBS ] = nm->stub_begin() ;
163 _section_end [CodeBuffer::SECT_CONSTS] = nm->consts_end() ;
164 _section_end [CodeBuffer::SECT_INSTS ] = nm->insts_end() ;
165 _section_end [CodeBuffer::SECT_STUBS ] = nm->stub_end() ;
167 assert(!has_current(), "just checking");
168 assert(begin == NULL || begin >= nm->code_begin(), "in bounds");
169 assert(limit == NULL || limit <= nm->code_end(), "in bounds");
170 set_limits(begin, limit);
171 }
174 RelocIterator::RelocIterator(CodeSection* cs, address begin, address limit) {
175 initialize_misc();
177 _current = cs->locs_start()-1;
178 _end = cs->locs_end();
179 _addr = cs->start();
180 _code = NULL; // Not cb->blob();
182 CodeBuffer* cb = cs->outer();
183 assert((int) SECT_LIMIT == CodeBuffer::SECT_LIMIT, "my copy must be equal");
184 for (int n = (int) CodeBuffer::SECT_FIRST; n < (int) CodeBuffer::SECT_LIMIT; n++) {
185 CodeSection* cs = cb->code_section(n);
186 _section_start[n] = cs->start();
187 _section_end [n] = cs->end();
188 }
190 assert(!has_current(), "just checking");
192 assert(begin == NULL || begin >= cs->start(), "in bounds");
193 assert(limit == NULL || limit <= cs->end(), "in bounds");
194 set_limits(begin, limit);
195 }
198 enum { indexCardSize = 128 };
199 struct RelocIndexEntry {
200 jint addr_offset; // offset from header_end of an addr()
201 jint reloc_offset; // offset from header_end of a relocInfo (prefix)
202 };
205 bool RelocIterator::addr_in_const() const {
206 const int n = CodeBuffer::SECT_CONSTS;
207 return section_start(n) <= addr() && addr() < section_end(n);
208 }
211 static inline int num_cards(int code_size) {
212 return (code_size-1) / indexCardSize;
213 }
216 int RelocIterator::locs_and_index_size(int code_size, int locs_size) {
217 if (!UseRelocIndex) return locs_size; // no index
218 code_size = round_to(code_size, oopSize);
219 locs_size = round_to(locs_size, oopSize);
220 int index_size = num_cards(code_size) * sizeof(RelocIndexEntry);
221 // format of indexed relocs:
222 // relocation_begin: relocInfo ...
223 // index: (addr,reloc#) ...
224 // indexSize :relocation_end
225 return locs_size + index_size + BytesPerInt;
226 }
229 void RelocIterator::create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end) {
230 address relocation_begin = (address)dest_begin;
231 address relocation_end = (address)dest_end;
232 int total_size = relocation_end - relocation_begin;
233 int locs_size = dest_count * sizeof(relocInfo);
234 if (!UseRelocIndex) {
235 Copy::fill_to_bytes(relocation_begin + locs_size, total_size-locs_size, 0);
236 return;
237 }
238 int index_size = total_size - locs_size - BytesPerInt; // find out how much space is left
239 int ncards = index_size / sizeof(RelocIndexEntry);
240 assert(total_size == locs_size + index_size + BytesPerInt, "checkin'");
241 assert(index_size >= 0 && index_size % sizeof(RelocIndexEntry) == 0, "checkin'");
242 jint* index_size_addr = (jint*)relocation_end - 1;
244 assert(sizeof(jint) == BytesPerInt, "change this code");
246 *index_size_addr = index_size;
247 if (index_size != 0) {
248 assert(index_size > 0, "checkin'");
250 RelocIndexEntry* index = (RelocIndexEntry *)(relocation_begin + locs_size);
251 assert(index == (RelocIndexEntry*)index_size_addr - ncards, "checkin'");
253 // walk over the relocations, and fill in index entries as we go
254 RelocIterator iter;
255 const address initial_addr = NULL;
256 relocInfo* const initial_current = dest_begin - 1; // biased by -1 like elsewhere
258 iter._code = NULL;
259 iter._addr = initial_addr;
260 iter._limit = (address)(intptr_t)(ncards * indexCardSize);
261 iter._current = initial_current;
262 iter._end = dest_begin + dest_count;
264 int i = 0;
265 address next_card_addr = (address)indexCardSize;
266 int addr_offset = 0;
267 int reloc_offset = 0;
268 while (true) {
269 // Checkpoint the iterator before advancing it.
270 addr_offset = iter._addr - initial_addr;
271 reloc_offset = iter._current - initial_current;
272 if (!iter.next()) break;
273 while (iter.addr() >= next_card_addr) {
274 index[i].addr_offset = addr_offset;
275 index[i].reloc_offset = reloc_offset;
276 i++;
277 next_card_addr += indexCardSize;
278 }
279 }
280 while (i < ncards) {
281 index[i].addr_offset = addr_offset;
282 index[i].reloc_offset = reloc_offset;
283 i++;
284 }
285 }
286 }
289 void RelocIterator::set_limits(address begin, address limit) {
290 int index_size = 0;
291 if (UseRelocIndex && _code != NULL) {
292 index_size = ((jint*)_end)[-1];
293 _end = (relocInfo*)( (address)_end - index_size - BytesPerInt );
294 }
296 _limit = limit;
298 // the limit affects this next stuff:
299 if (begin != NULL) {
300 #ifdef ASSERT
301 // In ASSERT mode we do not actually use the index, but simply
302 // check that its contents would have led us to the right answer.
303 address addrCheck = _addr;
304 relocInfo* infoCheck = _current;
305 #endif // ASSERT
306 if (index_size > 0) {
307 // skip ahead
308 RelocIndexEntry* index = (RelocIndexEntry*)_end;
309 RelocIndexEntry* index_limit = (RelocIndexEntry*)((address)index + index_size);
310 assert(_addr == _code->code_begin(), "_addr must be unadjusted");
311 int card = (begin - _addr) / indexCardSize;
312 if (card > 0) {
313 if (index+card-1 < index_limit) index += card-1;
314 else index = index_limit - 1;
315 #ifdef ASSERT
316 addrCheck = _addr + index->addr_offset;
317 infoCheck = _current + index->reloc_offset;
318 #else
319 // Advance the iterator immediately to the last valid state
320 // for the previous card. Calling "next" will then advance
321 // it to the first item on the required card.
322 _addr += index->addr_offset;
323 _current += index->reloc_offset;
324 #endif // ASSERT
325 }
326 }
328 relocInfo* backup;
329 address backup_addr;
330 while (true) {
331 backup = _current;
332 backup_addr = _addr;
333 #ifdef ASSERT
334 if (backup == infoCheck) {
335 assert(backup_addr == addrCheck, "must match"); addrCheck = NULL; infoCheck = NULL;
336 } else {
337 assert(addrCheck == NULL || backup_addr <= addrCheck, "must not pass addrCheck");
338 }
339 #endif // ASSERT
340 if (!next() || addr() >= begin) break;
341 }
342 assert(addrCheck == NULL || addrCheck == backup_addr, "must have matched addrCheck");
343 assert(infoCheck == NULL || infoCheck == backup, "must have matched infoCheck");
344 // At this point, either we are at the first matching record,
345 // or else there is no such record, and !has_current().
346 // In either case, revert to the immediatly preceding state.
347 _current = backup;
348 _addr = backup_addr;
349 set_has_current(false);
350 }
351 }
354 void RelocIterator::set_limit(address limit) {
355 address code_end = (address)code() + code()->size();
356 assert(limit == NULL || limit <= code_end, "in bounds");
357 _limit = limit;
358 }
361 void PatchingRelocIterator:: prepass() {
362 // turn breakpoints off during patching
363 _init_state = (*this); // save cursor
364 while (next()) {
365 if (type() == relocInfo::breakpoint_type) {
366 breakpoint_reloc()->set_active(false);
367 }
368 }
369 (RelocIterator&)(*this) = _init_state; // reset cursor for client
370 }
373 void PatchingRelocIterator:: postpass() {
374 // turn breakpoints back on after patching
375 (RelocIterator&)(*this) = _init_state; // reset cursor again
376 while (next()) {
377 if (type() == relocInfo::breakpoint_type) {
378 breakpoint_Relocation* bpt = breakpoint_reloc();
379 bpt->set_active(bpt->enabled());
380 }
381 }
382 }
385 // All the strange bit-encodings are in here.
386 // The idea is to encode relocation data which are small integers
387 // very efficiently (a single extra halfword). Larger chunks of
388 // relocation data need a halfword header to hold their size.
389 void RelocIterator::advance_over_prefix() {
390 if (_current->is_datalen()) {
391 _data = (short*) _current->data();
392 _datalen = _current->datalen();
393 _current += _datalen + 1; // skip the embedded data & header
394 } else {
395 _databuf = _current->immediate();
396 _data = &_databuf;
397 _datalen = 1;
398 _current++; // skip the header
399 }
400 // The client will see the following relocInfo, whatever that is.
401 // It is the reloc to which the preceding data applies.
402 }
405 void RelocIterator::initialize_misc() {
406 set_has_current(false);
407 for (int i = (int) CodeBuffer::SECT_FIRST; i < (int) CodeBuffer::SECT_LIMIT; i++) {
408 _section_start[i] = NULL; // these will be lazily computed, if needed
409 _section_end [i] = NULL;
410 }
411 }
414 Relocation* RelocIterator::reloc() {
415 // (take the "switch" out-of-line)
416 relocInfo::relocType t = type();
417 if (false) {}
418 #define EACH_TYPE(name) \
419 else if (t == relocInfo::name##_type) { \
420 return name##_reloc(); \
421 }
422 APPLY_TO_RELOCATIONS(EACH_TYPE);
423 #undef EACH_TYPE
424 assert(t == relocInfo::none, "must be padding");
425 return new(_rh) Relocation();
426 }
429 //////// Methods for flyweight Relocation types
432 RelocationHolder RelocationHolder::plus(int offset) const {
433 if (offset != 0) {
434 switch (type()) {
435 case relocInfo::none:
436 break;
437 case relocInfo::oop_type:
438 {
439 oop_Relocation* r = (oop_Relocation*)reloc();
440 return oop_Relocation::spec(r->oop_index(), r->offset() + offset);
441 }
442 default:
443 ShouldNotReachHere();
444 }
445 }
446 return (*this);
447 }
450 void Relocation::guarantee_size() {
451 guarantee(false, "Make _relocbuf bigger!");
452 }
454 // some relocations can compute their own values
455 address Relocation::value() {
456 ShouldNotReachHere();
457 return NULL;
458 }
461 void Relocation::set_value(address x) {
462 ShouldNotReachHere();
463 }
466 RelocationHolder Relocation::spec_simple(relocInfo::relocType rtype) {
467 if (rtype == relocInfo::none) return RelocationHolder::none;
468 relocInfo ri = relocInfo(rtype, 0);
469 RelocIterator itr;
470 itr.set_current(ri);
471 itr.reloc();
472 return itr._rh;
473 }
476 static inline bool is_index(intptr_t index) {
477 return 0 < index && index < os::vm_page_size();
478 }
481 int32_t Relocation::runtime_address_to_index(address runtime_address) {
482 assert(!is_index((intptr_t)runtime_address), "must not look like an index");
484 if (runtime_address == NULL) return 0;
486 StubCodeDesc* p = StubCodeDesc::desc_for(runtime_address);
487 if (p != NULL && p->begin() == runtime_address) {
488 assert(is_index(p->index()), "there must not be too many stubs");
489 return (int32_t)p->index();
490 } else {
491 // Known "miscellaneous" non-stub pointers:
492 // os::get_polling_page(), SafepointSynchronize::address_of_state()
493 if (PrintRelocations) {
494 tty->print_cr("random unregistered address in relocInfo: " INTPTR_FORMAT, runtime_address);
495 }
496 #ifndef _LP64
497 return (int32_t) (intptr_t)runtime_address;
498 #else
499 // didn't fit return non-index
500 return -1;
501 #endif /* _LP64 */
502 }
503 }
506 address Relocation::index_to_runtime_address(int32_t index) {
507 if (index == 0) return NULL;
509 if (is_index(index)) {
510 StubCodeDesc* p = StubCodeDesc::desc_for_index(index);
511 assert(p != NULL, "there must be a stub for this index");
512 return p->begin();
513 } else {
514 #ifndef _LP64
515 // this only works on 32bit machines
516 return (address) ((intptr_t) index);
517 #else
518 fatal("Relocation::index_to_runtime_address, int32_t not pointer sized");
519 return NULL;
520 #endif /* _LP64 */
521 }
522 }
524 address Relocation::old_addr_for(address newa,
525 const CodeBuffer* src, CodeBuffer* dest) {
526 int sect = dest->section_index_of(newa);
527 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
528 address ostart = src->code_section(sect)->start();
529 address nstart = dest->code_section(sect)->start();
530 return ostart + (newa - nstart);
531 }
533 address Relocation::new_addr_for(address olda,
534 const CodeBuffer* src, CodeBuffer* dest) {
535 debug_only(const CodeBuffer* src0 = src);
536 int sect = CodeBuffer::SECT_NONE;
537 // Look for olda in the source buffer, and all previous incarnations
538 // if the source buffer has been expanded.
539 for (; src != NULL; src = src->before_expand()) {
540 sect = src->section_index_of(olda);
541 if (sect != CodeBuffer::SECT_NONE) break;
542 }
543 guarantee(sect != CodeBuffer::SECT_NONE, "lost track of this address");
544 address ostart = src->code_section(sect)->start();
545 address nstart = dest->code_section(sect)->start();
546 return nstart + (olda - ostart);
547 }
549 void Relocation::normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections) {
550 address addr0 = addr;
551 if (addr0 == NULL || dest->allocates2(addr0)) return;
552 CodeBuffer* cb = dest->outer();
553 addr = new_addr_for(addr0, cb, cb);
554 assert(allow_other_sections || dest->contains2(addr),
555 "addr must be in required section");
556 }
559 void CallRelocation::set_destination(address x) {
560 pd_set_call_destination(x);
561 }
563 void CallRelocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
564 // Usually a self-relative reference to an external routine.
565 // On some platforms, the reference is absolute (not self-relative).
566 // The enhanced use of pd_call_destination sorts this all out.
567 address orig_addr = old_addr_for(addr(), src, dest);
568 address callee = pd_call_destination(orig_addr);
569 // Reassert the callee address, this time in the new copy of the code.
570 pd_set_call_destination(callee);
571 }
574 //// pack/unpack methods
576 void oop_Relocation::pack_data_to(CodeSection* dest) {
577 short* p = (short*) dest->locs_end();
578 p = pack_2_ints_to(p, _oop_index, _offset);
579 dest->set_locs_end((relocInfo*) p);
580 }
583 void oop_Relocation::unpack_data() {
584 unpack_2_ints(_oop_index, _offset);
585 }
588 void virtual_call_Relocation::pack_data_to(CodeSection* dest) {
589 short* p = (short*) dest->locs_end();
590 address point = dest->locs_point();
592 // Try to make a pointer NULL first.
593 if (_oop_limit >= point &&
594 _oop_limit <= point + NativeCall::instruction_size) {
595 _oop_limit = NULL;
596 }
597 // If the _oop_limit is NULL, it "defaults" to the end of the call.
598 // See ic_call_Relocation::oop_limit() below.
600 normalize_address(_first_oop, dest);
601 normalize_address(_oop_limit, dest);
602 jint x0 = scaled_offset_null_special(_first_oop, point);
603 jint x1 = scaled_offset_null_special(_oop_limit, point);
604 p = pack_2_ints_to(p, x0, x1);
605 dest->set_locs_end((relocInfo*) p);
606 }
609 void virtual_call_Relocation::unpack_data() {
610 jint x0, x1; unpack_2_ints(x0, x1);
611 address point = addr();
612 _first_oop = x0==0? NULL: address_from_scaled_offset(x0, point);
613 _oop_limit = x1==0? NULL: address_from_scaled_offset(x1, point);
614 }
617 void static_stub_Relocation::pack_data_to(CodeSection* dest) {
618 short* p = (short*) dest->locs_end();
619 CodeSection* insts = dest->outer()->insts();
620 normalize_address(_static_call, insts);
621 p = pack_1_int_to(p, scaled_offset(_static_call, insts->start()));
622 dest->set_locs_end((relocInfo*) p);
623 }
625 void static_stub_Relocation::unpack_data() {
626 address base = binding()->section_start(CodeBuffer::SECT_INSTS);
627 _static_call = address_from_scaled_offset(unpack_1_int(), base);
628 }
631 void external_word_Relocation::pack_data_to(CodeSection* dest) {
632 short* p = (short*) dest->locs_end();
633 int32_t index = runtime_address_to_index(_target);
634 #ifndef _LP64
635 p = pack_1_int_to(p, index);
636 #else
637 if (is_index(index)) {
638 p = pack_2_ints_to(p, index, 0);
639 } else {
640 jlong t = (jlong) _target;
641 int32_t lo = low(t);
642 int32_t hi = high(t);
643 p = pack_2_ints_to(p, lo, hi);
644 DEBUG_ONLY(jlong t1 = jlong_from(hi, lo));
645 assert(!is_index(t1) && (address) t1 == _target, "not symmetric");
646 }
647 #endif /* _LP64 */
648 dest->set_locs_end((relocInfo*) p);
649 }
652 void external_word_Relocation::unpack_data() {
653 #ifndef _LP64
654 _target = index_to_runtime_address(unpack_1_int());
655 #else
656 int32_t lo, hi;
657 unpack_2_ints(lo, hi);
658 jlong t = jlong_from(hi, lo);;
659 if (is_index(t)) {
660 _target = index_to_runtime_address(t);
661 } else {
662 _target = (address) t;
663 }
664 #endif /* _LP64 */
665 }
668 void internal_word_Relocation::pack_data_to(CodeSection* dest) {
669 short* p = (short*) dest->locs_end();
670 normalize_address(_target, dest, true);
672 // Check whether my target address is valid within this section.
673 // If not, strengthen the relocation type to point to another section.
674 int sindex = _section;
675 if (sindex == CodeBuffer::SECT_NONE && _target != NULL
676 && (!dest->allocates(_target) || _target == dest->locs_point())) {
677 sindex = dest->outer()->section_index_of(_target);
678 guarantee(sindex != CodeBuffer::SECT_NONE, "must belong somewhere");
679 relocInfo* base = dest->locs_end() - 1;
680 assert(base->type() == this->type(), "sanity");
681 // Change the written type, to be section_word_type instead.
682 base->set_type(relocInfo::section_word_type);
683 }
685 // Note: An internal_word relocation cannot refer to its own instruction,
686 // because we reserve "0" to mean that the pointer itself is embedded
687 // in the code stream. We use a section_word relocation for such cases.
689 if (sindex == CodeBuffer::SECT_NONE) {
690 assert(type() == relocInfo::internal_word_type, "must be base class");
691 guarantee(_target == NULL || dest->allocates2(_target), "must be within the given code section");
692 jint x0 = scaled_offset_null_special(_target, dest->locs_point());
693 assert(!(x0 == 0 && _target != NULL), "correct encoding of null target");
694 p = pack_1_int_to(p, x0);
695 } else {
696 assert(_target != NULL, "sanity");
697 CodeSection* sect = dest->outer()->code_section(sindex);
698 guarantee(sect->allocates2(_target), "must be in correct section");
699 address base = sect->start();
700 jint offset = scaled_offset(_target, base);
701 assert((uint)sindex < (uint)CodeBuffer::SECT_LIMIT, "sanity");
702 assert(CodeBuffer::SECT_LIMIT <= (1 << section_width), "section_width++");
703 p = pack_1_int_to(p, (offset << section_width) | sindex);
704 }
706 dest->set_locs_end((relocInfo*) p);
707 }
710 void internal_word_Relocation::unpack_data() {
711 jint x0 = unpack_1_int();
712 _target = x0==0? NULL: address_from_scaled_offset(x0, addr());
713 _section = CodeBuffer::SECT_NONE;
714 }
717 void section_word_Relocation::unpack_data() {
718 jint x = unpack_1_int();
719 jint offset = (x >> section_width);
720 int sindex = (x & ((1<<section_width)-1));
721 address base = binding()->section_start(sindex);
723 _section = sindex;
724 _target = address_from_scaled_offset(offset, base);
725 }
728 void breakpoint_Relocation::pack_data_to(CodeSection* dest) {
729 short* p = (short*) dest->locs_end();
730 address point = dest->locs_point();
732 *p++ = _bits;
734 assert(_target != NULL, "sanity");
736 if (internal()) normalize_address(_target, dest);
738 jint target_bits =
739 (jint)( internal() ? scaled_offset (_target, point)
740 : runtime_address_to_index(_target) );
741 if (settable()) {
742 // save space for set_target later
743 p = add_jint(p, target_bits);
744 } else {
745 p = add_var_int(p, target_bits);
746 }
748 for (int i = 0; i < instrlen(); i++) {
749 // put placeholder words until bytes can be saved
750 p = add_short(p, (short)0x7777);
751 }
753 dest->set_locs_end((relocInfo*) p);
754 }
757 void breakpoint_Relocation::unpack_data() {
758 _bits = live_bits();
760 int targetlen = datalen() - 1 - instrlen();
761 jint target_bits = 0;
762 if (targetlen == 0) target_bits = 0;
763 else if (targetlen == 1) target_bits = *(data()+1);
764 else if (targetlen == 2) target_bits = relocInfo::jint_from_data(data()+1);
765 else { ShouldNotReachHere(); }
767 _target = internal() ? address_from_scaled_offset(target_bits, addr())
768 : index_to_runtime_address (target_bits);
769 }
772 //// miscellaneous methods
773 oop* oop_Relocation::oop_addr() {
774 int n = _oop_index;
775 if (n == 0) {
776 // oop is stored in the code stream
777 return (oop*) pd_address_in_code();
778 } else {
779 // oop is stored in table at nmethod::oops_begin
780 return code()->oop_addr_at(n);
781 }
782 }
785 oop oop_Relocation::oop_value() {
786 oop v = *oop_addr();
787 // clean inline caches store a special pseudo-null
788 if (v == (oop)Universe::non_oop_word()) v = NULL;
789 return v;
790 }
793 void oop_Relocation::fix_oop_relocation() {
794 if (!oop_is_immediate()) {
795 // get the oop from the pool, and re-insert it into the instruction:
796 set_value(value());
797 }
798 }
801 void oop_Relocation::verify_oop_relocation() {
802 if (!oop_is_immediate()) {
803 // get the oop from the pool, and re-insert it into the instruction:
804 verify_value(value());
805 }
806 }
809 RelocIterator virtual_call_Relocation::parse_ic(nmethod* &nm, address &ic_call, address &first_oop,
810 oop* &oop_addr, bool *is_optimized) {
811 assert(ic_call != NULL, "ic_call address must be set");
812 assert(ic_call != NULL || first_oop != NULL, "must supply a non-null input");
813 if (nm == NULL) {
814 CodeBlob* code;
815 if (ic_call != NULL) {
816 code = CodeCache::find_blob(ic_call);
817 } else if (first_oop != NULL) {
818 code = CodeCache::find_blob(first_oop);
819 }
820 nm = code->as_nmethod_or_null();
821 assert(nm != NULL, "address to parse must be in nmethod");
822 }
823 assert(ic_call == NULL || nm->contains(ic_call), "must be in nmethod");
824 assert(first_oop == NULL || nm->contains(first_oop), "must be in nmethod");
826 address oop_limit = NULL;
828 if (ic_call != NULL) {
829 // search for the ic_call at the given address
830 RelocIterator iter(nm, ic_call, ic_call+1);
831 bool ret = iter.next();
832 assert(ret == true, "relocInfo must exist at this address");
833 assert(iter.addr() == ic_call, "must find ic_call");
834 if (iter.type() == relocInfo::virtual_call_type) {
835 virtual_call_Relocation* r = iter.virtual_call_reloc();
836 first_oop = r->first_oop();
837 oop_limit = r->oop_limit();
838 *is_optimized = false;
839 } else {
840 assert(iter.type() == relocInfo::opt_virtual_call_type, "must be a virtual call");
841 *is_optimized = true;
842 oop_addr = NULL;
843 first_oop = NULL;
844 return iter;
845 }
846 }
848 // search for the first_oop, to get its oop_addr
849 RelocIterator all_oops(nm, first_oop);
850 RelocIterator iter = all_oops;
851 iter.set_limit(first_oop+1);
852 bool found_oop = false;
853 while (iter.next()) {
854 if (iter.type() == relocInfo::oop_type) {
855 assert(iter.addr() == first_oop, "must find first_oop");
856 oop_addr = iter.oop_reloc()->oop_addr();
857 found_oop = true;
858 break;
859 }
860 }
861 assert(found_oop, "must find first_oop");
863 bool did_reset = false;
864 while (ic_call == NULL) {
865 // search forward for the ic_call matching the given first_oop
866 while (iter.next()) {
867 if (iter.type() == relocInfo::virtual_call_type) {
868 virtual_call_Relocation* r = iter.virtual_call_reloc();
869 if (r->first_oop() == first_oop) {
870 ic_call = r->addr();
871 oop_limit = r->oop_limit();
872 break;
873 }
874 }
875 }
876 guarantee(!did_reset, "cannot find ic_call");
877 iter = RelocIterator(nm); // search the whole nmethod
878 did_reset = true;
879 }
881 assert(oop_limit != NULL && first_oop != NULL && ic_call != NULL, "");
882 all_oops.set_limit(oop_limit);
883 return all_oops;
884 }
887 address virtual_call_Relocation::first_oop() {
888 assert(_first_oop != NULL && _first_oop < addr(), "must precede ic_call");
889 return _first_oop;
890 }
893 address virtual_call_Relocation::oop_limit() {
894 if (_oop_limit == NULL)
895 return addr() + NativeCall::instruction_size;
896 else
897 return _oop_limit;
898 }
902 void virtual_call_Relocation::clear_inline_cache() {
903 // No stubs for ICs
904 // Clean IC
905 ResourceMark rm;
906 CompiledIC* icache = CompiledIC_at(this);
907 icache->set_to_clean();
908 }
911 void opt_virtual_call_Relocation::clear_inline_cache() {
912 // No stubs for ICs
913 // Clean IC
914 ResourceMark rm;
915 CompiledIC* icache = CompiledIC_at(this);
916 icache->set_to_clean();
917 }
920 address opt_virtual_call_Relocation::static_stub() {
921 // search for the static stub who points back to this static call
922 address static_call_addr = addr();
923 RelocIterator iter(code());
924 while (iter.next()) {
925 if (iter.type() == relocInfo::static_stub_type) {
926 if (iter.static_stub_reloc()->static_call() == static_call_addr) {
927 return iter.addr();
928 }
929 }
930 }
931 return NULL;
932 }
935 void static_call_Relocation::clear_inline_cache() {
936 // Safe call site info
937 CompiledStaticCall* handler = compiledStaticCall_at(this);
938 handler->set_to_clean();
939 }
942 address static_call_Relocation::static_stub() {
943 // search for the static stub who points back to this static call
944 address static_call_addr = addr();
945 RelocIterator iter(code());
946 while (iter.next()) {
947 if (iter.type() == relocInfo::static_stub_type) {
948 if (iter.static_stub_reloc()->static_call() == static_call_addr) {
949 return iter.addr();
950 }
951 }
952 }
953 return NULL;
954 }
957 void static_stub_Relocation::clear_inline_cache() {
958 // Call stub is only used when calling the interpreted code.
959 // It does not really need to be cleared, except that we want to clean out the methodoop.
960 CompiledStaticCall::set_stub_to_clean(this);
961 }
964 void external_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
965 address target = _target;
966 if (target == NULL) {
967 // An absolute embedded reference to an external location,
968 // which means there is nothing to fix here.
969 return;
970 }
971 // Probably this reference is absolute, not relative, so the
972 // following is probably a no-op.
973 assert(src->section_index_of(target) == CodeBuffer::SECT_NONE, "sanity");
974 set_value(target);
975 }
978 address external_word_Relocation::target() {
979 address target = _target;
980 if (target == NULL) {
981 target = pd_get_address_from_code();
982 }
983 return target;
984 }
987 void internal_word_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
988 address target = _target;
989 if (target == NULL) {
990 if (addr_in_const()) {
991 target = new_addr_for(*(address*)addr(), src, dest);
992 } else {
993 target = new_addr_for(pd_get_address_from_code(), src, dest);
994 }
995 }
996 set_value(target);
997 }
1000 address internal_word_Relocation::target() {
1001 address target = _target;
1002 if (target == NULL) {
1003 target = pd_get_address_from_code();
1004 }
1005 return target;
1006 }
1009 breakpoint_Relocation::breakpoint_Relocation(int kind, address target, bool internal) {
1010 bool active = false;
1011 bool enabled = (kind == initialization);
1012 bool removable = (kind != safepoint);
1013 bool settable = (target == NULL);
1015 int bits = kind;
1016 if (enabled) bits |= enabled_state;
1017 if (internal) bits |= internal_attr;
1018 if (removable) bits |= removable_attr;
1019 if (settable) bits |= settable_attr;
1021 _bits = bits | high_bit;
1022 _target = target;
1024 assert(this->kind() == kind, "kind encoded");
1025 assert(this->enabled() == enabled, "enabled encoded");
1026 assert(this->active() == active, "active encoded");
1027 assert(this->internal() == internal, "internal encoded");
1028 assert(this->removable() == removable, "removable encoded");
1029 assert(this->settable() == settable, "settable encoded");
1030 }
1033 address breakpoint_Relocation::target() const {
1034 return _target;
1035 }
1038 void breakpoint_Relocation::set_target(address x) {
1039 assert(settable(), "must be settable");
1040 jint target_bits =
1041 (jint)(internal() ? scaled_offset (x, addr())
1042 : runtime_address_to_index(x));
1043 short* p = &live_bits() + 1;
1044 p = add_jint(p, target_bits);
1045 assert(p == instrs(), "new target must fit");
1046 _target = x;
1047 }
1050 void breakpoint_Relocation::set_enabled(bool b) {
1051 if (enabled() == b) return;
1053 if (b) {
1054 set_bits(bits() | enabled_state);
1055 } else {
1056 set_active(false); // remove the actual breakpoint insn, if any
1057 set_bits(bits() & ~enabled_state);
1058 }
1059 }
1062 void breakpoint_Relocation::set_active(bool b) {
1063 assert(!b || enabled(), "cannot activate a disabled breakpoint");
1065 if (active() == b) return;
1067 // %%% should probably seize a lock here (might not be the right lock)
1068 //MutexLockerEx ml_patch(Patching_lock, true);
1069 //if (active() == b) return; // recheck state after locking
1071 if (b) {
1072 set_bits(bits() | active_state);
1073 if (instrlen() == 0)
1074 fatal("breakpoints in original code must be undoable");
1075 pd_swap_in_breakpoint (addr(), instrs(), instrlen());
1076 } else {
1077 set_bits(bits() & ~active_state);
1078 pd_swap_out_breakpoint(addr(), instrs(), instrlen());
1079 }
1080 }
1083 //---------------------------------------------------------------------------------
1084 // Non-product code
1086 #ifndef PRODUCT
1088 static const char* reloc_type_string(relocInfo::relocType t) {
1089 switch (t) {
1090 #define EACH_CASE(name) \
1091 case relocInfo::name##_type: \
1092 return #name;
1094 APPLY_TO_RELOCATIONS(EACH_CASE);
1095 #undef EACH_CASE
1097 case relocInfo::none:
1098 return "none";
1099 case relocInfo::data_prefix_tag:
1100 return "prefix";
1101 default:
1102 return "UNKNOWN RELOC TYPE";
1103 }
1104 }
1107 void RelocIterator::print_current() {
1108 if (!has_current()) {
1109 tty->print_cr("(no relocs)");
1110 return;
1111 }
1112 tty->print("relocInfo@" INTPTR_FORMAT " [type=%d(%s) addr=" INTPTR_FORMAT " offset=%d",
1113 _current, type(), reloc_type_string((relocInfo::relocType) type()), _addr, _current->addr_offset());
1114 if (current()->format() != 0)
1115 tty->print(" format=%d", current()->format());
1116 if (datalen() == 1) {
1117 tty->print(" data=%d", data()[0]);
1118 } else if (datalen() > 0) {
1119 tty->print(" data={");
1120 for (int i = 0; i < datalen(); i++) {
1121 tty->print("%04x", data()[i] & 0xFFFF);
1122 }
1123 tty->print("}");
1124 }
1125 tty->print("]");
1126 switch (type()) {
1127 case relocInfo::oop_type:
1128 {
1129 oop_Relocation* r = oop_reloc();
1130 oop* oop_addr = NULL;
1131 oop raw_oop = NULL;
1132 oop oop_value = NULL;
1133 if (code() != NULL || r->oop_is_immediate()) {
1134 oop_addr = r->oop_addr();
1135 raw_oop = *oop_addr;
1136 oop_value = r->oop_value();
1137 }
1138 tty->print(" | [oop_addr=" INTPTR_FORMAT " *=" INTPTR_FORMAT " offset=%d]",
1139 oop_addr, (address)raw_oop, r->offset());
1140 // Do not print the oop by default--we want this routine to
1141 // work even during GC or other inconvenient times.
1142 if (WizardMode && oop_value != NULL) {
1143 tty->print("oop_value=" INTPTR_FORMAT ": ", (address)oop_value);
1144 oop_value->print_value_on(tty);
1145 }
1146 break;
1147 }
1148 case relocInfo::external_word_type:
1149 case relocInfo::internal_word_type:
1150 case relocInfo::section_word_type:
1151 {
1152 DataRelocation* r = (DataRelocation*) reloc();
1153 tty->print(" | [target=" INTPTR_FORMAT "]", r->value()); //value==target
1154 break;
1155 }
1156 case relocInfo::static_call_type:
1157 case relocInfo::runtime_call_type:
1158 {
1159 CallRelocation* r = (CallRelocation*) reloc();
1160 tty->print(" | [destination=" INTPTR_FORMAT "]", r->destination());
1161 break;
1162 }
1163 case relocInfo::virtual_call_type:
1164 {
1165 virtual_call_Relocation* r = (virtual_call_Relocation*) reloc();
1166 tty->print(" | [destination=" INTPTR_FORMAT " first_oop=" INTPTR_FORMAT " oop_limit=" INTPTR_FORMAT "]",
1167 r->destination(), r->first_oop(), r->oop_limit());
1168 break;
1169 }
1170 case relocInfo::static_stub_type:
1171 {
1172 static_stub_Relocation* r = (static_stub_Relocation*) reloc();
1173 tty->print(" | [static_call=" INTPTR_FORMAT "]", r->static_call());
1174 break;
1175 }
1176 }
1177 tty->cr();
1178 }
1181 void RelocIterator::print() {
1182 RelocIterator save_this = (*this);
1183 relocInfo* scan = _current;
1184 if (!has_current()) scan += 1; // nothing to scan here!
1186 bool skip_next = has_current();
1187 bool got_next;
1188 while (true) {
1189 got_next = (skip_next || next());
1190 skip_next = false;
1192 tty->print(" @" INTPTR_FORMAT ": ", scan);
1193 relocInfo* newscan = _current+1;
1194 if (!has_current()) newscan -= 1; // nothing to scan here!
1195 while (scan < newscan) {
1196 tty->print("%04x", *(short*)scan & 0xFFFF);
1197 scan++;
1198 }
1199 tty->cr();
1201 if (!got_next) break;
1202 print_current();
1203 }
1205 (*this) = save_this;
1206 }
1208 // For the debugger:
1209 extern "C"
1210 void print_blob_locs(nmethod* nm) {
1211 nm->print();
1212 RelocIterator iter(nm);
1213 iter.print();
1214 }
1215 extern "C"
1216 void print_buf_locs(CodeBuffer* cb) {
1217 FlagSetting fs(PrintRelocations, true);
1218 cb->print();
1219 }
1220 #endif // !PRODUCT