1 /*
   2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   4  * Copyright (c) 2015, Linaro Ltd. All rights reserved.
   5  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   6  *
   7  * This code is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 only, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  *
  25  */
  26 
  27 #include "precompiled.hpp"
  28 #include "interpreter/interpreter.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "oops/markOop.hpp"
  31 #include "oops/method.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "prims/methodHandles.hpp"
  34 #include "runtime/frame.inline.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #include "runtime/javaCalls.hpp"
  37 #include "runtime/monitorChunk.hpp"
  38 #include "runtime/os.hpp"
  39 #include "runtime/signature.hpp"
  40 #include "runtime/stubCodeGenerator.hpp"
  41 #include "runtime/stubRoutines.hpp"
  42 #include "vmreg_aarch32.inline.hpp"
  43 #ifdef COMPILER1
  44 #include "c1/c1_Runtime1.hpp"
  45 #include "runtime/vframeArray.hpp"
  46 #endif
  47 
  48 #ifdef ASSERT
  49 void RegisterMap::check_location_valid() {
  50 }
  51 #endif
  52 
  53 
  54 // Profiling/safepoint support
  55 
  56 bool frame::safe_for_sender(JavaThread *thread) {
  57   address   sp = (address)_sp;
  58   address   fp = (address)_fp;
  59   address   unextended_sp = (address)_unextended_sp;
  60 
  61   // consider stack guards when trying to determine "safe" stack pointers
  62   static size_t stack_guard_size = os::uses_stack_guard_pages() ? (StackYellowPages + StackRedPages) * os::vm_page_size() : 0;
  63   size_t usable_stack_size = thread->stack_size() - stack_guard_size;
  64 
  65   // sp must be within the usable part of the stack (not in guards)
  66   bool sp_safe = (sp < thread->stack_base()) &&
  67                  (sp >= thread->stack_base() - usable_stack_size);
  68 
  69 
  70   if (!sp_safe) {
  71     return false;
  72   }
  73 
  74   // unextended sp must be within the stack and above or equal sp
  75   bool unextended_sp_safe = (unextended_sp < thread->stack_base()) &&
  76                             (unextended_sp >= sp);
  77 
  78   if (!unextended_sp_safe) {
  79     return false;
  80   }
  81 
  82   // an fp must be within the stack and above (but not equal) sp
  83   // second evaluation on fp+ is added to handle situation where fp is -1
  84   bool fp_safe = (fp < thread->stack_base() && (fp > sp) && (((fp + (return_addr_offset * sizeof(void*))) < thread->stack_base())));
  85 
  86   // We know sp/unextended_sp are safe only fp is questionable here
  87 
  88   // If the current frame is known to the code cache then we can attempt to
  89   // to construct the sender and do some validation of it. This goes a long way
  90   // toward eliminating issues when we get in frame construction code
  91 
  92   if (_cb != NULL ) {
  93 
  94     // First check if frame is complete and tester is reliable
  95     // Unfortunately we can only check frame complete for runtime stubs and nmethod
  96     // other generic buffer blobs are more problematic so we just assume they are
  97     // ok. adapter blobs never have a frame complete and are never ok.
  98 
  99     if (!_cb->is_frame_complete_at(_pc)) {
 100       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 101         return false;
 102       }
 103     }
 104 
 105     // Could just be some random pointer within the codeBlob
 106     if (!_cb->code_contains(_pc)) {
 107       return false;
 108     }
 109 
 110     // Entry frame checks
 111     if (is_entry_frame()) {
 112       // an entry frame must have a valid fp.
 113 
 114       if (!fp_safe) return false;
 115 
 116       // Validate the JavaCallWrapper an entry frame must have
 117 
 118       address jcw = (address)entry_frame_call_wrapper();
 119 
 120       bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > fp);
 121 
 122       return jcw_safe;
 123 
 124     }
 125 
 126     intptr_t* sender_sp = NULL;
 127     intptr_t* sender_unextended_sp = NULL;
 128     address   sender_pc = NULL;
 129     intptr_t* saved_fp =  NULL;
 130 
 131     if (is_interpreted_frame()) {
 132       // fp must be safe
 133       if (!fp_safe) {
 134         return false;
 135       }
 136 
 137       sender_pc = (address) this->fp()[return_addr_offset];
 138       // for interpreted frames, the value below is the sender "raw" sp,
 139       // which can be different from the sender unextended sp (the sp seen
 140       // by the sender) because of current frame local variables
 141       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
 142       sender_unextended_sp = (intptr_t*) this->fp()[interpreter_frame_sender_sp_offset];
 143       saved_fp = (intptr_t*) this->fp()[link_offset];
 144 
 145     } else {
 146       // must be some sort of compiled/runtime frame
 147       // fp does not have to be safe (although it could be check for c1?)
 148 
 149       // check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
 150       if (_cb->frame_size() <= 0) {
 151         return false;
 152       }
 153 
 154       sender_sp = _unextended_sp + _cb->frame_size();
 155       sender_unextended_sp = sender_sp;
 156       sender_pc = (address) *(sender_sp - 1);
 157       // Note: frame::sender_sp_offset is only valid for compiled frame
 158       saved_fp = (intptr_t*) *(sender_sp - 2);
 159     }
 160 
 161 
 162     // If the potential sender is the interpreter then we can do some more checking
 163     if (Interpreter::contains(sender_pc)) {
 164 
 165       // fp is always saved in a recognizable place in any code we generate. However
 166       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved fp
 167       // is really a frame pointer.
 168 
 169       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 170 
 171       if (!saved_fp_safe) {
 172         return false;
 173       }
 174 
 175       // construct the potential sender
 176 
 177       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
 178 
 179       return sender.is_interpreted_frame_valid(thread);
 180 
 181     }
 182 
 183     // We must always be able to find a recognizable pc
 184     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 185     if (sender_pc == NULL ||  sender_blob == NULL) {
 186       return false;
 187     }
 188 
 189     // Could be a zombie method
 190     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
 191       return false;
 192     }
 193 
 194     // Could just be some random pointer within the codeBlob
 195     if (!sender_blob->code_contains(sender_pc)) {
 196       return false;
 197     }
 198 
 199     // We should never be able to see an adapter if the current frame is something from code cache
 200     if (sender_blob->is_adapter_blob()) {
 201       return false;
 202     }
 203 
 204     // Could be the call_stub
 205     if (StubRoutines::returns_to_call_stub(sender_pc)) {
 206       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 207 
 208       if (!saved_fp_safe) {
 209         return false;
 210       }
 211 
 212       // construct the potential sender
 213 
 214       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
 215 
 216       // Validate the JavaCallWrapper an entry frame must have
 217       address jcw = (address)sender.entry_frame_call_wrapper();
 218 
 219       bool jcw_safe = (jcw < thread->stack_base()) && ( jcw > (address)sender.fp());
 220 
 221       return jcw_safe;
 222     }
 223 
 224     if (sender_blob->is_nmethod()) {
 225         nmethod* nm = sender_blob->as_nmethod_or_null();
 226         if (nm != NULL) {
 227             if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc) ||
 228                 nm->method()->is_method_handle_intrinsic()) {
 229                 return false;
 230             }
 231         }
 232     }
 233 
 234     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
 235     // because the return address counts against the callee's frame.
 236 
 237     if (sender_blob->frame_size() <= 0) {
 238       assert(!sender_blob->is_nmethod(), "should count return address at least");
 239       return false;
 240     }
 241 
 242     // We should never be able to see anything here except an nmethod. If something in the
 243     // code cache (current frame) is called by an entity within the code cache that entity
 244     // should not be anything but the call stub (already covered), the interpreter (already covered)
 245     // or an nmethod.
 246 
 247     if (!sender_blob->is_nmethod()) {
 248         return false;
 249     }
 250 
 251     // Could put some more validation for the potential non-interpreted sender
 252     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 253 
 254     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 255 
 256     // We've validated the potential sender that would be created
 257     return true;
 258   }
 259 
 260   // Must be native-compiled frame. Since sender will try and use fp to find
 261   // linkages it must be safe
 262 
 263   if (!fp_safe) {
 264     return false;
 265   }
 266 
 267   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
 268 
 269   if ( (address) this->fp()[return_addr_offset] == NULL) return false;
 270 
 271 
 272   // could try and do some more potential verification of native frame if we could think of some...
 273 
 274   return true;
 275 
 276 }
 277 
 278 void frame::patch_pc(Thread* thread, address pc) {
 279   address* pc_addr = &(((address*) sp())[-1]);
 280   if (TracePcPatching) {
 281     tty->print_cr("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
 282                   p2i(pc_addr), p2i(*pc_addr), p2i(pc));
 283   }
 284   // Either the return address is the original one or we are going to
 285   // patch in the same address that's already there.
 286   assert(_pc == *pc_addr || pc == *pc_addr, "must be");
 287   *pc_addr = pc;
 288   _cb = CodeCache::find_blob(pc);
 289   address original_pc = nmethod::get_deopt_original_pc(this);
 290   if (original_pc != NULL) {
 291     assert(original_pc == _pc, "expected original PC to be stored before patching");
 292     _deopt_state = is_deoptimized;
 293     // leave _pc as is
 294   } else {
 295     _deopt_state = not_deoptimized;
 296     _pc = pc;
 297   }
 298 }
 299 
 300 bool frame::is_interpreted_frame() const  {
 301   return Interpreter::contains(pc());
 302 }
 303 
 304 int frame::frame_size(RegisterMap* map) const {
 305   frame sender = this->sender(map);
 306   return sender.sp() - sp();
 307 }
 308 
 309 intptr_t* frame::entry_frame_argument_at(int offset) const {
 310   // convert offset to index to deal with tsi
 311   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 312   // Entry frame's arguments are always in relation to unextended_sp()
 313   return &unextended_sp()[index];
 314 }
 315 
 316 // sender_sp
 317 #ifdef CC_INTERP
 318 intptr_t* frame::interpreter_frame_sender_sp() const {
 319   assert(is_interpreted_frame(), "interpreted frame expected");
 320   // QQQ why does this specialize method exist if frame::sender_sp() does same thing?
 321   // seems odd and if we always know interpreted vs. non then sender_sp() is really
 322   // doing too much work.
 323   return get_interpreterState()->sender_sp();
 324 }
 325 
 326 // monitor elements
 327 
 328 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
 329   return get_interpreterState()->monitor_base();
 330 }
 331 
 332 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
 333   return (BasicObjectLock*) get_interpreterState()->stack_base();
 334 }
 335 
 336 #else // CC_INTERP
 337 
 338 intptr_t* frame::interpreter_frame_sender_sp() const {
 339   assert(is_interpreted_frame(), "interpreted frame expected");
 340   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
 341 }
 342 
 343 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 344   assert(is_interpreted_frame(), "interpreted frame expected");
 345   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
 346 }
 347 
 348 
 349 // monitor elements
 350 
 351 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
 352   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
 353 }
 354 
 355 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
 356   BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
 357   // make sure the pointer points inside the frame
 358   assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
 359   assert((intptr_t*) result < fp(),  "monitor end should be strictly below the frame pointer");
 360   return result;
 361 }
 362 
 363 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
 364   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
 365 }
 366 
 367 // Used by template based interpreter deoptimization
 368 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
 369     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
 370 }
 371 #endif // CC_INTERP
 372 
 373 frame frame::sender_for_entry_frame(RegisterMap* map) const {
 374   assert(map != NULL, "map must be set");
 375   // Java frame called from C; skip all C frames and return top C
 376   // frame of that chunk as the sender
 377   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 378   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 379   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
 380   // Since we are walking the stack now this nested anchor is obviously walkable
 381   // even if it wasn't when it was stacked.
 382   if (!jfa->walkable()) {
 383     // Capture _last_Java_pc (if needed) and mark anchor walkable.
 384     jfa->capture_last_Java_pc();
 385   }
 386   map->clear();
 387   assert(map->include_argument_oops(), "should be set by clear");
 388   assert(jfa->last_Java_pc() != NULL, "not walkable");
 389   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
 390   return fr;
 391 }
 392 
 393 //------------------------------------------------------------------------------
 394 // frame::verify_deopt_original_pc
 395 //
 396 // Verifies the calculated original PC of a deoptimization PC for the
 397 // given unextended SP.
 398 #ifdef ASSERT
 399 void frame::verify_deopt_original_pc(nmethod* nm, intptr_t* unextended_sp) {
 400   frame fr;
 401 
 402   // This is ugly but it's better than to change {get,set}_original_pc
 403   // to take an SP value as argument.  And it's only a debugging
 404   // method anyway.
 405   fr._unextended_sp = unextended_sp;
 406 
 407   address original_pc = nm->get_original_pc(&fr);
 408   assert(nm->insts_contains(original_pc), "original PC must be in nmethod");
 409 }
 410 #endif
 411 
 412 //------------------------------------------------------------------------------
 413 // frame::adjust_unextended_sp
 414 void frame::adjust_unextended_sp() {
 415   // On aarch32, sites calling method handle intrinsics and lambda forms are treated
 416   // as any other call site. Therefore, no special action is needed when we are
 417   // returning to any of these call sites.
 418 
 419   nmethod* sender_nm = (_cb == NULL) ? NULL : _cb->as_nmethod_or_null();
 420   if (sender_nm != NULL) {
 421     // If the sender PC is a deoptimization point, get the original PC.
 422     if (sender_nm->is_deopt_entry(_pc) ||
 423         sender_nm->is_deopt_mh_entry(_pc)) {
 424       DEBUG_ONLY(verify_deopt_original_pc(sender_nm, _unextended_sp));
 425     }
 426   }
 427 }
 428 
 429 //------------------------------------------------------------------------------
 430 // frame::update_map_with_saved_link
 431 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
 432   // The interpreter and compiler(s) always save fp in a known
 433   // location on entry. We must record where that location is
 434   // so that if fp was live on callout from c2 we can find
 435   // the saved copy no matter what it called.
 436 
 437   // Since the interpreter always saves fp if we record where it is then
 438   // we don't have to always save fp on entry and exit to c2 compiled
 439   // code, on entry will be enough.
 440   map->set_location(rfp->as_VMReg(), (address) link_addr);
 441 }
 442 
 443 
 444 //------------------------------------------------------------------------------
 445 // frame::sender_for_interpreter_frame
 446 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
 447   // SP is the raw SP from the sender after adapter or interpreter
 448   // extension.
 449   intptr_t* sender_sp = this->sender_sp();
 450 
 451   // This is the sp before any possible extension (adapter/locals).
 452   intptr_t* unextended_sp = interpreter_frame_sender_sp();
 453 
 454 #ifdef COMPILER2
 455   if (map->update_map()) {
 456     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
 457   }
 458 #endif // COMPILER2
 459 
 460   return frame(sender_sp, unextended_sp, link(), sender_pc());
 461 }
 462 
 463 
 464 //------------------------------------------------------------------------------
 465 // frame::sender_for_compiled_frame
 466 /*frame frame::sender_for_compiled_frame(RegisterMap* map) const {
 467   // we cannot rely upon the last fp having been saved to the thread
 468   // in C2 code but it will have been pushed onto the stack. so we
 469   // have to find it relative to the unextended sp
 470 
 471   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
 472   intptr_t* l_sender_sp = unextended_sp() + _cb->frame_size();
 473   intptr_t* unextended_sp = l_sender_sp;
 474 
 475   // the return_address is always the word on the stack
 476   address sender_pc = (address) *(l_sender_sp-1);
 477 
 478   intptr_t** saved_fp_addr = (intptr_t**) (l_sender_sp - frame::sender_sp_offset);
 479   intptr_t** saved_fp_addr = (intptr_t**)(_fp + link_offset);
 480 
 481   // assert (sender_sp() == l_sender_sp, "should be");
 482   // assert (*saved_fp_addr == link(), "should be");
 483 
 484   if (map->update_map()) {
 485     // Tell GC to use argument oopmaps for some runtime stubs that need it.
 486     // For C1, the runtime stub might not have oop maps, so set this flag
 487     // outside of update_register_map.
 488     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 489     if (_cb->oop_maps() != NULL) {
 490       OopMapSet::update_register_map(this, map);
 491     }
 492 
 493     // Since the prolog does the save and restore of FP there is no
 494     // oopmap for it so we must fill in its location as if there was
 495     // an oopmap entry since if our caller was compiled code there
 496     // could be live jvm state in it.
 497     update_map_with_saved_link(map, saved_fp_addr);
 498   }
 499 
 500   return frame(l_sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
 501 }*/
 502 
 503 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
 504   // we cannot rely upon the last fp having been saved to the thread
 505   // in C2 code but it will have been pushed onto the stack. so we
 506   // have to find it relative to the unextended sp
 507 
 508   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
 509   intptr_t* l_sender_sp = unextended_sp() + _cb->frame_size();
 510   intptr_t* unextended_sp = l_sender_sp;
 511 
 512   // the return_address is always the word on the stack
 513   address sender_pc = (address) *(l_sender_sp - 1);
 514 
 515   intptr_t** saved_fp_addr = (intptr_t**)(l_sender_sp - 2);
 516 
 517   // assert (sender_sp() == l_sender_sp, "should be");
 518   // assert (*saved_fp_addr == link(), "should be");
 519 
 520   if (map->update_map()) {
 521     // Tell GC to use argument oopmaps for some runtime stubs that need it.
 522     // For C1, the runtime stub might not have oop maps, so set this flag
 523     // outside of update_register_map.
 524     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 525     if (_cb->oop_maps() != NULL) {
 526       OopMapSet::update_register_map(this, map);
 527     }
 528 
 529     // Since the prolog does the save and restore of FP there is no
 530     // oopmap for it so we must fill in its location as if there was
 531     // an oopmap entry since if our caller was compiled code there
 532     // could be live jvm state in it.
 533     update_map_with_saved_link(map, saved_fp_addr);
 534   }
 535 
 536   return frame(l_sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
 537 }
 538 
 539 //------------------------------------------------------------------------------
 540 // frame::sender
 541 frame frame::sender(RegisterMap* map) const {
 542   // Default is we done have to follow them. The sender_for_xxx will
 543   // update it accordingly
 544   map->set_include_argument_oops(false);
 545   //printf("Called frame::sender\n");
 546 
 547   //printf("fp is %p, _call_stub_return_address is %p\n", _fp, StubRoutines::_call_stub_return_address);
 548 
 549   if (is_entry_frame()) {
 550     //printf("Is entry frame\n");
 551     return sender_for_entry_frame(map);
 552   }
 553   if (is_interpreted_frame()) {
 554     //printf("Is interpreted frame\n");
 555     return sender_for_interpreter_frame(map);
 556   }
 557   assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
 558 
 559   // This test looks odd: why is it not is_compiled_frame() ?  That's
 560   // because stubs also have OOP maps.
 561   if (_cb != NULL) {
 562     //printf("Is compiled frame\n");
 563     return sender_for_compiled_frame(map);
 564   }
 565 
 566   //printf("Is default frame\n");
 567   // Must be native-compiled frame, i.e. the marshaling code for native
 568   // methods that exists in the core system.
 569   return frame(sender_sp(), link(), sender_pc());
 570 }
 571 
 572 bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {
 573   assert(is_interpreted_frame(), "must be interpreter frame");
 574   Method* method = interpreter_frame_method();
 575   // When unpacking an optimized frame the frame pointer is
 576   // adjusted with:
 577   int diff = (method->max_locals() - method->size_of_parameters()) *
 578              Interpreter::stackElementWords;
 579   return _fp == (fp - diff);
 580 }
 581 
 582 void frame::pd_gc_epilog() {
 583   // Nothing to do here for now
 584 }
 585 
 586 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 587 // QQQ
 588 #ifdef CC_INTERP
 589 #else
 590   assert(is_interpreted_frame(), "Not an interpreted frame");
 591   // These are reasonable sanity checks
 592   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
 593     return false;
 594   }
 595   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
 596     return false;
 597   }
 598   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 599     return false;
 600   }
 601   // These are hacks to keep us out of trouble.
 602   // The problem with these is that they mask other problems
 603   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 604     return false;
 605   }
 606 
 607   // do some validation of frame elements
 608 
 609   // first the method
 610 
 611   Method* m = *interpreter_frame_method_addr();
 612 
 613   // validate the method we'd find in this potential sender
 614   if (!m->is_valid_method()) return false;
 615 
 616   // stack frames shouldn't be much larger than max_stack elements
 617   // this test requires the use of unextended_sp which is the sp as seen by
 618   // the current frame, and not sp which is the "raw" pc which could point
 619   // further because of local variables of the callee method inserted after
 620   // method arguments
 621   if (fp() - unextended_sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 622     return false;
 623   }
 624 
 625   // Validate bci/bcx
 626   intptr_t bcx = interpreter_frame_bcx();
 627   if (m->validate_bci_from_bcx(bcx) < 0) {
 628     return false;
 629   }
 630 
 631   // validate constantPoolCache*
 632   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
 633   if (cp == NULL || !cp->is_metaspace_object()) return false;
 634 
 635   // validate locals
 636 
 637   address locals =  (address) *interpreter_frame_locals_addr();
 638 
 639   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 640 
 641   // We'd have to be pretty unlucky to be mislead at this point
 642 
 643 #endif // CC_INTERP
 644   return true;
 645 }
 646 
 647 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 648 #ifdef CC_INTERP
 649   // Needed for JVMTI. The result should always be in the
 650   // interpreterState object
 651   interpreterState istate = get_interpreterState();
 652 #endif // CC_INTERP
 653   assert(is_interpreted_frame(), "interpreted frame expected");
 654   Method* method = interpreter_frame_method();
 655   BasicType type = method->result_type();
 656 
 657   intptr_t* tos_addr;
 658   if (method->is_native()) {
 659     tos_addr = (intptr_t*)sp();
 660     if (type == T_FLOAT || type == T_DOUBLE) {
 661       // This is times two because we do a push(ltos) after pushing D0
 662       // and that takes two interpreter stack slots.
 663 #ifdef HARD_FLOAT_CC
 664       tos_addr += 2 * Interpreter::stackElementWords;
 665 #endif
 666     }
 667   } else {
 668     tos_addr = (intptr_t*)interpreter_frame_tos_address();
 669   }
 670 
 671   switch (type) {
 672     case T_OBJECT  :
 673     case T_ARRAY   : {
 674       oop obj;
 675       if (method->is_native()) {
 676 #ifdef CC_INTERP
 677         obj = istate->_oop_temp;
 678 #else
 679         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
 680 #endif // CC_INTERP
 681       } else {
 682         oop* obj_p = (oop*)tos_addr;
 683         obj = (obj_p == NULL) ? (oop)NULL : *obj_p;
 684       }
 685       assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 686       *oop_result = obj;
 687       break;
 688     }
 689     case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
 690     case T_BYTE    : value_result->b = *(jbyte*)tos_addr; break;
 691     case T_CHAR    : value_result->c = *(jchar*)tos_addr; break;
 692     case T_SHORT   : value_result->s = *(jshort*)tos_addr; break;
 693     case T_INT     : value_result->i = *(jint*)tos_addr; break;
 694     case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 695     case T_FLOAT   : {
 696         value_result->f = *(jfloat*)tos_addr;
 697       break;
 698     }
 699     case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 700     case T_VOID    : /* Nothing to do */ break;
 701     default        : ShouldNotReachHere();
 702   }
 703 
 704   return type;
 705 }
 706 
 707 
 708 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 709   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 710   return &interpreter_frame_tos_address()[index];
 711 }
 712 
 713 #ifndef PRODUCT
 714 
 715 #define DESCRIBE_FP_OFFSET(name) \
 716     values.describe(frame_no, fp() + frame::name##_offset, #name)
 717 
 718 void frame::describe_pd(FrameValues& values, int frame_no) {
 719   if (is_interpreted_frame()) {
 720     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
 721     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
 722     DESCRIBE_FP_OFFSET(interpreter_frame_method);
 723     DESCRIBE_FP_OFFSET(interpreter_frame_mdx);
 724     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
 725     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
 726     DESCRIBE_FP_OFFSET(interpreter_frame_bcx);
 727     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
 728   }
 729 }
 730 
 731 #endif // PRODUCT
 732 
 733 intptr_t *frame::initial_deoptimization_info() {
 734   // Not used on aarch32, but we must return something.
 735   return NULL;
 736 }
 737 
 738 intptr_t* frame::real_fp() const {
 739   // Currently we have a fp for all frames
 740   /*if (_cb != NULL) {
 741     // use the frame size if valid
 742     int size = _cb->frame_size();
 743     if (size > 0) {
 744       return unextended_sp() + size;
 745     }
 746   }*/
 747   // else rely on fp()
 748   //assert(! is_compiled_frame(), "unknown compiled frame size");
 749   return fp();
 750 }
 751 
 752 #undef DESCRIBE_FP_OFFSET
 753 
 754 #define DESCRIBE_FP_OFFSET(name)                                        \
 755   {                                                                     \
 756     unsigned long *p = (unsigned long *)fp;                             \
 757     printf("0x%016lx 0x%016lx %s\n", (unsigned long)(p + frame::name##_offset), \
 758            p[frame::name##_offset], #name);                             \
 759   }
 760 
 761 static __thread unsigned long nextfp;
 762 static __thread unsigned long nextpc;
 763 static __thread unsigned long nextsp;
 764 static __thread RegisterMap *reg_map;
 765 
 766 static void printbc(Method* m, intptr_t bcx) {
 767   const char* name;
 768   char buf[16];
 769   if (m->validate_bci_from_bcx(bcx) < 0 || !m->contains((address) bcx)) {
 770     name = "???";
 771     snprintf(buf, sizeof buf, "(bad)");
 772   } else {
 773     int bci = m->bci_from((address) bcx);
 774     snprintf(buf, sizeof buf, "%d", bci);
 775     name = Bytecodes::name(m->code_at(bci));
 776   }
 777   ResourceMark rm;
 778   printf("%s : %s ==> %s\n", m->name_and_sig_as_C_string(), buf, name);
 779 }
 780 
 781 void internal_pf(unsigned long sp, unsigned long fp, unsigned long pc, unsigned long bcx) {
 782   if (! fp)
 783     return;
 784 
 785   DESCRIBE_FP_OFFSET(return_addr);
 786   DESCRIBE_FP_OFFSET(link);
 787   DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
 788   DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
 789   DESCRIBE_FP_OFFSET(interpreter_frame_method);
 790   DESCRIBE_FP_OFFSET(interpreter_frame_mdx);
 791   DESCRIBE_FP_OFFSET(interpreter_frame_cache);
 792   DESCRIBE_FP_OFFSET(interpreter_frame_locals);
 793   DESCRIBE_FP_OFFSET(interpreter_frame_bcx);
 794   DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
 795 
 796   unsigned long* p = (unsigned long*) fp;
 797 
 798   // We want to see all frames, native and Java.  For compiled and
 799   // interpreted frames we have special information that allows us to
 800   // unwind them; for everything else we assume that the native frame
 801   // pointer chain is intact.
 802   frame this_frame((intptr_t*)sp, (intptr_t*)fp, (address)pc);
 803   if (this_frame.is_compiled_frame() ||
 804       this_frame.is_interpreted_frame()) {
 805     frame sender = this_frame.sender(reg_map);
 806     nextfp = (unsigned long)sender.fp();
 807     nextpc = (unsigned long)sender.pc();
 808     nextsp = (unsigned long)sender.unextended_sp();
 809   } else {
 810     nextfp = p[frame::link_offset];
 811     nextpc = p[frame::return_addr_offset];
 812     nextsp = (unsigned long)&p[frame::sender_sp_offset];
 813   }
 814 
 815   if (bcx == -1ul) {
 816     bcx = p[frame::interpreter_frame_bcx_offset];
 817   }
 818 
 819   if (Interpreter::contains((address)pc)) {
 820     Method* m = (Method*)p[frame::interpreter_frame_method_offset];
 821     if(m && m->is_method()) {
 822       printbc(m, bcx);
 823     } else
 824       printf("not a Method\n");
 825   } else {
 826     CodeBlob *cb = CodeCache::find_blob((address)pc);
 827     if (cb != NULL) {
 828       if (cb->is_nmethod()) {
 829         ResourceMark rm;
 830         nmethod* nm = (nmethod*)cb;
 831         printf("nmethod %s\n", nm->method()->name_and_sig_as_C_string());
 832       } else if (cb->name()) {
 833         printf("CodeBlob %s\n", cb->name());
 834       }
 835     }
 836   }
 837 }
 838 
 839 extern "C" void npf() {
 840   CodeBlob *cb = CodeCache::find_blob((address)nextpc);
 841   // C2 does not always chain the frame pointers when it can, instead
 842   // preferring to use fixed offsets from SP, so a simple leave() does
 843   // not work.  Instead, it adds the frame size to SP then pops FP and
 844   // LR.  We have to do the same thing to get a good call chain.
 845   if (cb && cb->frame_size())
 846     nextfp = nextsp + wordSize * (cb->frame_size() - 2);
 847   internal_pf (nextsp, nextfp, nextpc, -1);
 848 }
 849 
 850 extern "C" void pf(unsigned long sp, unsigned long fp, unsigned long pc,
 851                    unsigned long bcx, unsigned long thread) {
 852   RegisterMap map((JavaThread*)thread, false);
 853   if (!reg_map) {
 854     reg_map = (RegisterMap*)os::malloc(sizeof map, mtNone);
 855   }
 856   memcpy(reg_map, &map, sizeof map);
 857   {
 858     CodeBlob *cb = CodeCache::find_blob((address)pc);
 859     if (cb && cb->frame_size())
 860       fp = sp + wordSize * (cb->frame_size() - 2);
 861   }
 862   internal_pf(sp, fp, pc, bcx);
 863 }
 864 
 865 // support for printing out where we are in a Java method
 866 // needs to be passed current fp and bcp register values
 867 // prints method name, bc index and bytecode name
 868 extern "C" void pm(unsigned long fp, unsigned long bcx) {
 869   DESCRIBE_FP_OFFSET(interpreter_frame_method);
 870   unsigned long *p = (unsigned long *)fp;
 871   Method* m = (Method*)p[frame::interpreter_frame_method_offset];
 872   printbc(m, bcx);
 873 }
 874 
 875 #ifndef PRODUCT
 876 // This is a generic constructor which is only used by pns() in debug.cpp.
 877 frame::frame(void* sp, void* fp, void* pc) {
 878   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
 879 }
 880 #endif
 881 
 882 void JavaFrameAnchor::make_walkable(JavaThread* thread) {
 883   // last frame set?
 884   if (last_Java_sp() == NULL) return;
 885   // already walkable?
 886   if (walkable()) return;
 887   assert(Thread::current() == (Thread*)thread, "not current thread");
 888   assert(last_Java_sp() != NULL, "not called from Java code?");
 889   assert(last_Java_pc() == NULL, "already walkable");
 890   capture_last_Java_pc();
 891   assert(walkable(), "something went wrong");
 892 }
 893 
 894 void JavaFrameAnchor::capture_last_Java_pc() {
 895   assert(_last_Java_sp != NULL, "no last frame set");
 896   assert(_last_Java_pc == NULL, "already walkable");
 897   _last_Java_pc = (address)_last_Java_sp[-1];
 898 }