1 /*
   2  * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "interpreter/interpreter.hpp"
  28 #include "memory/resourceArea.hpp"
  29 #include "oops/markOop.hpp"
  30 #include "oops/method.hpp"
  31 #include "oops/oop.inline.hpp"
  32 #include "prims/methodHandles.hpp"
  33 #include "runtime/frame.inline.hpp"
  34 #include "runtime/handles.inline.hpp"
  35 #include "runtime/javaCalls.hpp"
  36 #include "runtime/monitorChunk.hpp"
  37 #include "runtime/os.hpp"
  38 #include "runtime/signature.hpp"
  39 #include "runtime/stubCodeGenerator.hpp"
  40 #include "runtime/stubRoutines.hpp"
  41 #include "vmreg_aarch64.inline.hpp"
  42 #ifdef COMPILER1
  43 #include "c1/c1_Runtime1.hpp"
  44 #include "runtime/vframeArray.hpp"
  45 #endif
  46 
  47 #ifdef ASSERT
  48 void RegisterMap::check_location_valid() {
  49 }
  50 #endif
  51 
  52 
  53 // Profiling/safepoint support
  54 
  55 bool frame::safe_for_sender(JavaThread *thread) {
  56   address   sp = (address)_sp;
  57   address   fp = (address)_fp;
  58   address   unextended_sp = (address)_unextended_sp;
  59 
  60   // consider stack guards when trying to determine "safe" stack pointers
  61   static size_t stack_guard_size = os::uses_stack_guard_pages() ?
  62     (JavaThread::stack_red_zone_size() + JavaThread::stack_yellow_zone_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       return fp_safe && is_entry_frame_valid(thread);
 114     }
 115 
 116     intptr_t* sender_sp = NULL;
 117     intptr_t* sender_unextended_sp = NULL;
 118     address   sender_pc = NULL;
 119     intptr_t* saved_fp =  NULL;
 120 
 121     if (is_interpreted_frame()) {
 122       // fp must be safe
 123       if (!fp_safe) {
 124         return false;
 125       }
 126 
 127       sender_pc = (address) this->fp()[return_addr_offset];
 128       // for interpreted frames, the value below is the sender "raw" sp,
 129       // which can be different from the sender unextended sp (the sp seen
 130       // by the sender) because of current frame local variables
 131       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
 132       sender_unextended_sp = (intptr_t*) this->fp()[interpreter_frame_sender_sp_offset];
 133       saved_fp = (intptr_t*) this->fp()[link_offset];
 134 
 135     } else {
 136       // must be some sort of compiled/runtime frame
 137       // fp does not have to be safe (although it could be check for c1?)
 138 
 139       // check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
 140       if (_cb->frame_size() <= 0) {
 141         return false;
 142       }
 143 
 144       sender_sp = _unextended_sp + _cb->frame_size();
 145       // Is sender_sp safe?
 146       if ((address)sender_sp >= thread->stack_base()) {
 147         return false;
 148       }
 149       sender_unextended_sp = sender_sp;
 150       sender_pc = (address) *(sender_sp-1);
 151       // Note: frame::sender_sp_offset is only valid for compiled frame
 152       saved_fp = (intptr_t*) *(sender_sp - frame::sender_sp_offset);
 153     }
 154 
 155 
 156     // If the potential sender is the interpreter then we can do some more checking
 157     if (Interpreter::contains(sender_pc)) {
 158 
 159       // fp is always saved in a recognizable place in any code we generate. However
 160       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved fp
 161       // is really a frame pointer.
 162 
 163       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 164 
 165       if (!saved_fp_safe) {
 166         return false;
 167       }
 168 
 169       // construct the potential sender
 170 
 171       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
 172 
 173       return sender.is_interpreted_frame_valid(thread);
 174 
 175     }
 176 
 177     // We must always be able to find a recognizable pc
 178     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 179     if (sender_pc == NULL ||  sender_blob == NULL) {
 180       return false;
 181     }
 182 
 183     // Could be a zombie method
 184     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
 185       return false;
 186     }
 187 
 188     // Could just be some random pointer within the codeBlob
 189     if (!sender_blob->code_contains(sender_pc)) {
 190       return false;
 191     }
 192 
 193     // We should never be able to see an adapter if the current frame is something from code cache
 194     if (sender_blob->is_adapter_blob()) {
 195       return false;
 196     }
 197 
 198     // Could be the call_stub
 199     if (StubRoutines::returns_to_call_stub(sender_pc)) {
 200       bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
 201 
 202       if (!saved_fp_safe) {
 203         return false;
 204       }
 205 
 206       // construct the potential sender
 207 
 208       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
 209 
 210       // Validate the JavaCallWrapper an entry frame must have
 211       address jcw = (address)sender.entry_frame_call_wrapper();
 212 
 213       bool jcw_safe = (jcw < thread->stack_base()) && (jcw > (address)sender.fp());
 214 
 215       return jcw_safe;
 216     }
 217 
 218     CompiledMethod* nm = sender_blob->as_compiled_method_or_null();
 219     if (nm != NULL) {
 220       if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc) ||
 221           nm->method()->is_method_handle_intrinsic()) {
 222         return false;
 223       }
 224     }
 225 
 226     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
 227     // because the return address counts against the callee's frame.
 228 
 229     if (sender_blob->frame_size() <= 0) {
 230       assert(!sender_blob->is_compiled(), "should count return address at least");
 231       return false;
 232     }
 233 
 234     // We should never be able to see anything here except an nmethod. If something in the
 235     // code cache (current frame) is called by an entity within the code cache that entity
 236     // should not be anything but the call stub (already covered), the interpreter (already covered)
 237     // or an nmethod.
 238 
 239     if (!sender_blob->is_compiled()) {
 240         return false;
 241     }
 242 
 243     // Could put some more validation for the potential non-interpreted sender
 244     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 245 
 246     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 247 
 248     // We've validated the potential sender that would be created
 249     return true;
 250   }
 251 
 252   // Must be native-compiled frame. Since sender will try and use fp to find
 253   // linkages it must be safe
 254 
 255   if (!fp_safe) {
 256     return false;
 257   }
 258 
 259   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
 260 
 261   if ( (address) this->fp()[return_addr_offset] == NULL) return false;
 262 
 263 
 264   // could try and do some more potential verification of native frame if we could think of some...
 265 
 266   return true;
 267 
 268 }
 269 
 270 void frame::patch_pc(Thread* thread, address pc) {
 271   address* pc_addr = &(((address*) sp())[-1]);
 272   if (TracePcPatching) {
 273     tty->print_cr("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
 274                   p2i(pc_addr), p2i(*pc_addr), p2i(pc));
 275   }
 276   // Either the return address is the original one or we are going to
 277   // patch in the same address that's already there.
 278   assert(_pc == *pc_addr || pc == *pc_addr, "must be");
 279   *pc_addr = pc;
 280   _cb = CodeCache::find_blob(pc);
 281   address original_pc = CompiledMethod::get_deopt_original_pc(this);
 282   if (original_pc != NULL) {
 283     assert(original_pc == _pc, "expected original PC to be stored before patching");
 284     _deopt_state = is_deoptimized;
 285     // leave _pc as is
 286   } else {
 287     _deopt_state = not_deoptimized;
 288     _pc = pc;
 289   }
 290 }
 291 
 292 bool frame::is_interpreted_frame() const  {
 293   return Interpreter::contains(pc());
 294 }
 295 
 296 int frame::frame_size(RegisterMap* map) const {
 297   frame sender = this->sender(map);
 298   return sender.sp() - sp();
 299 }
 300 
 301 intptr_t* frame::entry_frame_argument_at(int offset) const {
 302   // convert offset to index to deal with tsi
 303   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 304   // Entry frame's arguments are always in relation to unextended_sp()
 305   return &unextended_sp()[index];
 306 }
 307 
 308 // sender_sp
 309 intptr_t* frame::interpreter_frame_sender_sp() const {
 310   assert(is_interpreted_frame(), "interpreted frame expected");
 311   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
 312 }
 313 
 314 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 315   assert(is_interpreted_frame(), "interpreted frame expected");
 316   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
 317 }
 318 
 319 
 320 // monitor elements
 321 
 322 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
 323   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
 324 }
 325 
 326 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
 327   BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
 328   // make sure the pointer points inside the frame
 329   assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
 330   assert((intptr_t*) result < fp(),  "monitor end should be strictly below the frame pointer");
 331   return result;
 332 }
 333 
 334 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
 335   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
 336 }
 337 
 338 // Used by template based interpreter deoptimization
 339 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
 340     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
 341 }
 342 
 343 frame frame::sender_for_entry_frame(RegisterMap* map) const {
 344   assert(map != NULL, "map must be set");
 345   // Java frame called from C; skip all C frames and return top C
 346   // frame of that chunk as the sender
 347   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 348   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 349   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
 350   // Since we are walking the stack now this nested anchor is obviously walkable
 351   // even if it wasn't when it was stacked.
 352   if (!jfa->walkable()) {
 353     // Capture _last_Java_pc (if needed) and mark anchor walkable.
 354     jfa->capture_last_Java_pc();
 355   }
 356   map->clear();
 357   assert(map->include_argument_oops(), "should be set by clear");
 358   vmassert(jfa->last_Java_pc() != NULL, "not walkable");
 359   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
 360   return fr;
 361 }
 362 
 363 //------------------------------------------------------------------------------
 364 // frame::verify_deopt_original_pc
 365 //
 366 // Verifies the calculated original PC of a deoptimization PC for the
 367 // given unextended SP.
 368 #ifdef ASSERT
 369 void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp) {
 370   frame fr;
 371 
 372   // This is ugly but it's better than to change {get,set}_original_pc
 373   // to take an SP value as argument.  And it's only a debugging
 374   // method anyway.
 375   fr._unextended_sp = unextended_sp;
 376 
 377   address original_pc = nm->get_original_pc(&fr);
 378   assert(nm->insts_contains_inclusive(original_pc),
 379          "original PC must be in the main code section of the the compiled method (or must be immediately following it)");
 380 }
 381 #endif
 382 
 383 //------------------------------------------------------------------------------
 384 // frame::adjust_unextended_sp
 385 void frame::adjust_unextended_sp() {
 386   // On aarch64, sites calling method handle intrinsics and lambda forms are treated
 387   // as any other call site. Therefore, no special action is needed when we are
 388   // returning to any of these call sites.
 389 
 390   if (_cb != NULL) {
 391     CompiledMethod* sender_cm = _cb->as_compiled_method_or_null();
 392     if (sender_cm != NULL) {
 393       // If the sender PC is a deoptimization point, get the original PC.
 394       if (sender_cm->is_deopt_entry(_pc) ||
 395           sender_cm->is_deopt_mh_entry(_pc)) {
 396         DEBUG_ONLY(verify_deopt_original_pc(sender_cm, _unextended_sp));
 397       }
 398     }
 399   }
 400 }
 401 
 402 //------------------------------------------------------------------------------
 403 // frame::update_map_with_saved_link
 404 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
 405   // The interpreter and compiler(s) always save fp in a known
 406   // location on entry. We must record where that location is
 407   // so that if fp was live on callout from c2 we can find
 408   // the saved copy no matter what it called.
 409 
 410   // Since the interpreter always saves fp if we record where it is then
 411   // we don't have to always save fp on entry and exit to c2 compiled
 412   // code, on entry will be enough.
 413   map->set_location(rfp->as_VMReg(), (address) link_addr);
 414   // this is weird "H" ought to be at a higher address however the
 415   // oopMaps seems to have the "H" regs at the same address and the
 416   // vanilla register.
 417   // XXXX make this go away
 418   if (true) {
 419     map->set_location(rfp->as_VMReg()->next(), (address) link_addr);
 420   }
 421 }
 422 
 423 
 424 //------------------------------------------------------------------------------
 425 // frame::sender_for_interpreter_frame
 426 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
 427   // SP is the raw SP from the sender after adapter or interpreter
 428   // extension.
 429   intptr_t* sender_sp = this->sender_sp();
 430 
 431   // This is the sp before any possible extension (adapter/locals).
 432   intptr_t* unextended_sp = interpreter_frame_sender_sp();
 433 
 434 #if defined(COMPILER2) || INCLUDE_JVMCI
 435   if (map->update_map()) {
 436     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
 437   }
 438 #endif // COMPILER2 || INCLUDE_JVMCI
 439 
 440   return frame(sender_sp, unextended_sp, link(), sender_pc());
 441 }
 442 
 443 
 444 //------------------------------------------------------------------------------
 445 // frame::sender_for_compiled_frame
 446 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
 447   // we cannot rely upon the last fp having been saved to the thread
 448   // in C2 code but it will have been pushed onto the stack. so we
 449   // have to find it relative to the unextended sp
 450 
 451   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
 452   intptr_t* l_sender_sp = unextended_sp() + _cb->frame_size();
 453   intptr_t* unextended_sp = l_sender_sp;
 454 
 455   // the return_address is always the word on the stack
 456   address sender_pc = (address) *(l_sender_sp-1);
 457 
 458   intptr_t** saved_fp_addr = (intptr_t**) (l_sender_sp - frame::sender_sp_offset);
 459 
 460   // assert (sender_sp() == l_sender_sp, "should be");
 461   // assert (*saved_fp_addr == link(), "should be");
 462 
 463   if (map->update_map()) {
 464     // Tell GC to use argument oopmaps for some runtime stubs that need it.
 465     // For C1, the runtime stub might not have oop maps, so set this flag
 466     // outside of update_register_map.
 467     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 468     if (_cb->oop_maps() != NULL) {
 469       OopMapSet::update_register_map(this, map);
 470     }
 471 
 472     // Since the prolog does the save and restore of FP there is no
 473     // oopmap for it so we must fill in its location as if there was
 474     // an oopmap entry since if our caller was compiled code there
 475     // could be live jvm state in it.
 476     update_map_with_saved_link(map, saved_fp_addr);
 477   }
 478 
 479   return frame(l_sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
 480 }
 481 
 482 //------------------------------------------------------------------------------
 483 // frame::sender
 484 frame frame::sender(RegisterMap* map) const {
 485   // Default is we done have to follow them. The sender_for_xxx will
 486   // update it accordingly
 487    map->set_include_argument_oops(false);
 488 
 489   if (is_entry_frame())
 490     return sender_for_entry_frame(map);
 491   if (is_interpreted_frame())
 492     return sender_for_interpreter_frame(map);
 493   assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
 494 
 495   // This test looks odd: why is it not is_compiled_frame() ?  That's
 496   // because stubs also have OOP maps.
 497   if (_cb != NULL) {
 498     return sender_for_compiled_frame(map);
 499   }
 500 
 501   // Must be native-compiled frame, i.e. the marshaling code for native
 502   // methods that exists in the core system.
 503   return frame(sender_sp(), link(), sender_pc());
 504 }
 505 
 506 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 507   assert(is_interpreted_frame(), "Not an interpreted frame");
 508   // These are reasonable sanity checks
 509   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
 510     return false;
 511   }
 512   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
 513     return false;
 514   }
 515   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 516     return false;
 517   }
 518   // These are hacks to keep us out of trouble.
 519   // The problem with these is that they mask other problems
 520   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 521     return false;
 522   }
 523 
 524   // do some validation of frame elements
 525 
 526   // first the method
 527 
 528   Method* m = *interpreter_frame_method_addr();
 529 
 530   // validate the method we'd find in this potential sender
 531   if (!m->is_valid_method()) return false;
 532 
 533   // stack frames shouldn't be much larger than max_stack elements
 534   // this test requires the use of unextended_sp which is the sp as seen by
 535   // the current frame, and not sp which is the "raw" pc which could point
 536   // further because of local variables of the callee method inserted after
 537   // method arguments
 538   if (fp() - unextended_sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 539     return false;
 540   }
 541 
 542   // validate bci/bcx
 543 
 544   address  bcp    = interpreter_frame_bcp();
 545   if (m->validate_bci_from_bcp(bcp) < 0) {
 546     return false;
 547   }
 548 
 549   // validate constantPoolCache*
 550   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
 551   if (cp == NULL || !cp->is_metaspace_object()) return false;
 552 
 553   // validate locals
 554 
 555   address locals =  (address) *interpreter_frame_locals_addr();
 556 
 557   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 558 
 559   // We'd have to be pretty unlucky to be mislead at this point
 560   return true;
 561 }
 562 
 563 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 564   assert(is_interpreted_frame(), "interpreted frame expected");
 565   Method* method = interpreter_frame_method();
 566   BasicType type = method->result_type();
 567 
 568   intptr_t* tos_addr;
 569   if (method->is_native()) {
 570     // TODO : ensure AARCH64 does the same as Intel here i.e. push v0 then r0
 571     // Prior to calling into the runtime to report the method_exit the possible
 572     // return value is pushed to the native stack. If the result is a jfloat/jdouble
 573     // then ST0 is saved before EAX/EDX. See the note in generate_native_result
 574     tos_addr = (intptr_t*)sp();
 575     if (type == T_FLOAT || type == T_DOUBLE) {
 576       // This is times two because we do a push(ltos) after pushing XMM0
 577       // and that takes two interpreter stack slots.
 578       tos_addr += 2 * Interpreter::stackElementWords;
 579     }
 580   } else {
 581     tos_addr = (intptr_t*)interpreter_frame_tos_address();
 582   }
 583 
 584   switch (type) {
 585     case T_OBJECT  :
 586     case T_ARRAY   : {
 587       oop obj;
 588       if (method->is_native()) {
 589         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
 590       } else {
 591         oop* obj_p = (oop*)tos_addr;
 592         obj = (obj_p == NULL) ? (oop)NULL : *obj_p;
 593       }
 594       assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 595       *oop_result = obj;
 596       break;
 597     }
 598     case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
 599     case T_BYTE    : value_result->b = *(jbyte*)tos_addr; break;
 600     case T_CHAR    : value_result->c = *(jchar*)tos_addr; break;
 601     case T_SHORT   : value_result->s = *(jshort*)tos_addr; break;
 602     case T_INT     : value_result->i = *(jint*)tos_addr; break;
 603     case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 604     case T_FLOAT   : {
 605         value_result->f = *(jfloat*)tos_addr;
 606       break;
 607     }
 608     case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 609     case T_VOID    : /* Nothing to do */ break;
 610     default        : ShouldNotReachHere();
 611   }
 612 
 613   return type;
 614 }
 615 
 616 
 617 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 618   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 619   return &interpreter_frame_tos_address()[index];
 620 }
 621 
 622 #ifndef PRODUCT
 623 
 624 #define DESCRIBE_FP_OFFSET(name) \
 625   values.describe(frame_no, fp() + frame::name##_offset, #name)
 626 
 627 void frame::describe_pd(FrameValues& values, int frame_no) {
 628   if (is_interpreted_frame()) {
 629     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
 630     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
 631     DESCRIBE_FP_OFFSET(interpreter_frame_method);
 632     DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
 633     DESCRIBE_FP_OFFSET(interpreter_frame_mirror);
 634     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
 635     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
 636     DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
 637     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
 638   }
 639 }
 640 #endif
 641 
 642 intptr_t *frame::initial_deoptimization_info() {
 643   // Not used on aarch64, but we must return something.
 644   return NULL;
 645 }
 646 
 647 intptr_t* frame::real_fp() const {
 648   if (_cb != NULL) {
 649     // use the frame size if valid
 650     int size = _cb->frame_size();
 651     if (size > 0) {
 652       return unextended_sp() + size;
 653     }
 654   }
 655   // else rely on fp()
 656   assert(! is_compiled_frame(), "unknown compiled frame size");
 657   return fp();
 658 }
 659 
 660 #undef DESCRIBE_FP_OFFSET
 661 
 662 #define DESCRIBE_FP_OFFSET(name)                                        \
 663   {                                                                     \
 664     unsigned long *p = (unsigned long *)fp;                             \
 665     printf("0x%016lx 0x%016lx %s\n", (unsigned long)(p + frame::name##_offset), \
 666            p[frame::name##_offset], #name);                             \
 667   }
 668 
 669 static __thread unsigned long nextfp;
 670 static __thread unsigned long nextpc;
 671 static __thread unsigned long nextsp;
 672 static __thread RegisterMap *reg_map;
 673 
 674 static void printbc(Method *m, intptr_t bcx) {
 675   const char *name;
 676   char buf[16];
 677   if (m->validate_bci_from_bcp((address)bcx) < 0
 678       || !m->contains((address)bcx)) {
 679     name = "???";
 680     snprintf(buf, sizeof buf, "(bad)");
 681   } else {
 682     int bci = m->bci_from((address)bcx);
 683     snprintf(buf, sizeof buf, "%d", bci);
 684     name = Bytecodes::name(m->code_at(bci));
 685   }
 686   ResourceMark rm;
 687   printf("%s : %s ==> %s\n", m->name_and_sig_as_C_string(), buf, name);
 688 }
 689 
 690 void internal_pf(unsigned long sp, unsigned long fp, unsigned long pc, unsigned long bcx) {
 691   if (! fp)
 692     return;
 693 
 694   DESCRIBE_FP_OFFSET(return_addr);
 695   DESCRIBE_FP_OFFSET(link);
 696   DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
 697   DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
 698   DESCRIBE_FP_OFFSET(interpreter_frame_method);
 699   DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
 700   DESCRIBE_FP_OFFSET(interpreter_frame_cache);
 701   DESCRIBE_FP_OFFSET(interpreter_frame_locals);
 702   DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
 703   DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
 704   unsigned long *p = (unsigned long *)fp;
 705 
 706   // We want to see all frames, native and Java.  For compiled and
 707   // interpreted frames we have special information that allows us to
 708   // unwind them; for everything else we assume that the native frame
 709   // pointer chain is intact.
 710   frame this_frame((intptr_t*)sp, (intptr_t*)fp, (address)pc);
 711   if (this_frame.is_compiled_frame() ||
 712       this_frame.is_interpreted_frame()) {
 713     frame sender = this_frame.sender(reg_map);
 714     nextfp = (unsigned long)sender.fp();
 715     nextpc = (unsigned long)sender.pc();
 716     nextsp = (unsigned long)sender.unextended_sp();
 717   } else {
 718     nextfp = p[frame::link_offset];
 719     nextpc = p[frame::return_addr_offset];
 720     nextsp = (unsigned long)&p[frame::sender_sp_offset];
 721   }
 722 
 723   if (bcx == -1ul)
 724     bcx = p[frame::interpreter_frame_bcp_offset];
 725 
 726   if (Interpreter::contains((address)pc)) {
 727     Method* m = (Method*)p[frame::interpreter_frame_method_offset];
 728     if(m && m->is_method()) {
 729       printbc(m, bcx);
 730     } else
 731       printf("not a Method\n");
 732   } else {
 733     CodeBlob *cb = CodeCache::find_blob((address)pc);
 734     if (cb != NULL) {
 735       if (cb->is_nmethod()) {
 736         ResourceMark rm;
 737         nmethod* nm = (nmethod*)cb;
 738         printf("nmethod %s\n", nm->method()->name_and_sig_as_C_string());
 739       } else if (cb->name()) {
 740         printf("CodeBlob %s\n", cb->name());
 741       }
 742     }
 743   }
 744 }
 745 
 746 extern "C" void npf() {
 747   CodeBlob *cb = CodeCache::find_blob((address)nextpc);
 748   // C2 does not always chain the frame pointers when it can, instead
 749   // preferring to use fixed offsets from SP, so a simple leave() does
 750   // not work.  Instead, it adds the frame size to SP then pops FP and
 751   // LR.  We have to do the same thing to get a good call chain.
 752   if (cb && cb->frame_size())
 753     nextfp = nextsp + wordSize * (cb->frame_size() - 2);
 754   internal_pf (nextsp, nextfp, nextpc, -1);
 755 }
 756 
 757 extern "C" void pf(unsigned long sp, unsigned long fp, unsigned long pc,
 758                    unsigned long bcx, unsigned long thread) {
 759   RegisterMap map((JavaThread*)thread, false);
 760   if (!reg_map) {
 761     reg_map = (RegisterMap*)os::malloc(sizeof map, mtNone);
 762   }
 763   memcpy(reg_map, &map, sizeof map);
 764   {
 765     CodeBlob *cb = CodeCache::find_blob((address)pc);
 766     if (cb && cb->frame_size())
 767       fp = sp + wordSize * (cb->frame_size() - 2);
 768   }
 769   internal_pf(sp, fp, pc, bcx);
 770 }
 771 
 772 // support for printing out where we are in a Java method
 773 // needs to be passed current fp and bcp register values
 774 // prints method name, bc index and bytecode name
 775 extern "C" void pm(unsigned long fp, unsigned long bcx) {
 776   DESCRIBE_FP_OFFSET(interpreter_frame_method);
 777   unsigned long *p = (unsigned long *)fp;
 778   Method* m = (Method*)p[frame::interpreter_frame_method_offset];
 779   printbc(m, bcx);
 780 }
 781 
 782 #ifndef PRODUCT
 783 // This is a generic constructor which is only used by pns() in debug.cpp.
 784 frame::frame(void* sp, void* fp, void* pc) {
 785   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
 786 }
 787 
 788 void frame::pd_ps() {}
 789 #endif
 790 
 791 void JavaFrameAnchor::make_walkable(JavaThread* thread) {
 792   // last frame set?
 793   if (last_Java_sp() == NULL) return;
 794   // already walkable?
 795   if (walkable()) return;
 796   vmassert(Thread::current() == (Thread*)thread, "not current thread");
 797   vmassert(last_Java_sp() != NULL, "not called from Java code?");
 798   vmassert(last_Java_pc() == NULL, "already walkable");
 799   capture_last_Java_pc();
 800   vmassert(walkable(), "something went wrong");
 801 }
 802 
 803 void JavaFrameAnchor::capture_last_Java_pc() {
 804   vmassert(_last_Java_sp != NULL, "no last frame set");
 805   vmassert(_last_Java_pc == NULL, "already walkable");
 806   _last_Java_pc = (address)_last_Java_sp[-1];
 807 }