1 /*
   2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "interpreter/interpreter.hpp"
  27 #include "memory/resourceArea.hpp"
  28 #include "oops/markOop.hpp"
  29 #include "oops/methodOop.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "runtime/frame.inline.hpp"
  32 #include "runtime/handles.inline.hpp"
  33 #include "runtime/javaCalls.hpp"
  34 #include "runtime/monitorChunk.hpp"
  35 #include "runtime/signature.hpp"
  36 #include "runtime/stubCodeGenerator.hpp"
  37 #include "runtime/stubRoutines.hpp"
  38 #include "vmreg_sparc.inline.hpp"
  39 #ifdef COMPILER1
  40 #include "c1/c1_Runtime1.hpp"
  41 #include "runtime/vframeArray.hpp"
  42 #endif
  43 
  44 void RegisterMap::pd_clear() {
  45   if (_thread->has_last_Java_frame()) {
  46     frame fr = _thread->last_frame();
  47     _window = fr.sp();
  48   } else {
  49     _window = NULL;
  50   }
  51   _younger_window = NULL;
  52 }
  53 
  54 
  55 // Unified register numbering scheme: each 32-bits counts as a register
  56 // number, so all the V9 registers take 2 slots.
  57 const static int R_L_nums[] = {0+040,2+040,4+040,6+040,8+040,10+040,12+040,14+040};
  58 const static int R_I_nums[] = {0+060,2+060,4+060,6+060,8+060,10+060,12+060,14+060};
  59 const static int R_O_nums[] = {0+020,2+020,4+020,6+020,8+020,10+020,12+020,14+020};
  60 const static int R_G_nums[] = {0+000,2+000,4+000,6+000,8+000,10+000,12+000,14+000};
  61 static RegisterMap::LocationValidType bad_mask = 0;
  62 static RegisterMap::LocationValidType R_LIO_mask = 0;
  63 static bool register_map_inited = false;
  64 
  65 static void register_map_init() {
  66   if (!register_map_inited) {
  67     register_map_inited = true;
  68     int i;
  69     for (i = 0; i < 8; i++) {
  70       assert(R_L_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  71       assert(R_I_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  72       assert(R_O_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  73       assert(R_G_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  74     }
  75 
  76     bad_mask |= (1LL << R_O_nums[6]); // SP
  77     bad_mask |= (1LL << R_O_nums[7]); // cPC
  78     bad_mask |= (1LL << R_I_nums[6]); // FP
  79     bad_mask |= (1LL << R_I_nums[7]); // rPC
  80     bad_mask |= (1LL << R_G_nums[2]); // TLS
  81     bad_mask |= (1LL << R_G_nums[7]); // reserved by libthread
  82 
  83     for (i = 0; i < 8; i++) {
  84       R_LIO_mask |= (1LL << R_L_nums[i]);
  85       R_LIO_mask |= (1LL << R_I_nums[i]);
  86       R_LIO_mask |= (1LL << R_O_nums[i]);
  87     }
  88   }
  89 }
  90 
  91 
  92 address RegisterMap::pd_location(VMReg regname) const {
  93   register_map_init();
  94 
  95   assert(regname->is_reg(), "sanity check");
  96   // Only the GPRs get handled this way
  97   if( !regname->is_Register())
  98     return NULL;
  99 
 100   // don't talk about bad registers
 101   if ((bad_mask & ((LocationValidType)1 << regname->value())) != 0) {
 102     return NULL;
 103   }
 104 
 105   // Convert to a GPR
 106   Register reg;
 107   int second_word = 0;
 108   // 32-bit registers for in, out and local
 109   if (!regname->is_concrete()) {
 110     // HMM ought to return NULL for any non-concrete (odd) vmreg
 111     // this all tied up in the fact we put out double oopMaps for
 112     // register locations. When that is fixed we'd will return NULL
 113     // (or assert here).
 114     reg = regname->prev()->as_Register();
 115 #ifdef _LP64
 116     second_word = sizeof(jint);
 117 #else
 118     return NULL;
 119 #endif // _LP64
 120   } else {
 121     reg = regname->as_Register();
 122   }
 123   if (reg->is_out()) {
 124     assert(_younger_window != NULL, "Younger window should be available");
 125     return second_word + (address)&_younger_window[reg->after_save()->sp_offset_in_saved_window()];
 126   }
 127   if (reg->is_local() || reg->is_in()) {
 128     assert(_window != NULL, "Window should be available");
 129     return second_word + (address)&_window[reg->sp_offset_in_saved_window()];
 130   }
 131   // Only the window'd GPRs get handled this way; not the globals.
 132   return NULL;
 133 }
 134 
 135 
 136 #ifdef ASSERT
 137 void RegisterMap::check_location_valid() {
 138   register_map_init();
 139   assert((_location_valid[0] & bad_mask) == 0, "cannot have special locations for SP,FP,TLS,etc.");
 140 }
 141 #endif
 142 
 143 // We are shifting windows.  That means we are moving all %i to %o,
 144 // getting rid of all current %l, and keeping all %g.  This is only
 145 // complicated if any of the location pointers for these are valid.
 146 // The normal case is that everything is in its standard register window
 147 // home, and _location_valid[0] is zero.  In that case, this routine
 148 // does exactly nothing.
 149 void RegisterMap::shift_individual_registers() {
 150   if (!update_map())  return;  // this only applies to maps with locations
 151   register_map_init();
 152   check_location_valid();
 153 
 154   LocationValidType lv = _location_valid[0];
 155   LocationValidType lv0 = lv;
 156 
 157   lv &= ~R_LIO_mask;  // clear %l, %o, %i regs
 158 
 159   // if we cleared some non-%g locations, we may have to do some shifting
 160   if (lv != lv0) {
 161     // copy %i0-%i5 to %o0-%o5, if they have special locations
 162     // This can happen in within stubs which spill argument registers
 163     // around a dynamic link operation, such as resolve_opt_virtual_call.
 164     for (int i = 0; i < 8; i++) {
 165       if (lv0 & (1LL << R_I_nums[i])) {
 166         _location[R_O_nums[i]] = _location[R_I_nums[i]];
 167         lv |=  (1LL << R_O_nums[i]);
 168       }
 169     }
 170   }
 171 
 172   _location_valid[0] = lv;
 173   check_location_valid();
 174 }
 175 
 176 bool frame::safe_for_sender(JavaThread *thread) {
 177 
 178   address _SP = (address) sp();
 179   address _FP = (address) fp();
 180   address _UNEXTENDED_SP = (address) unextended_sp();
 181   // sp must be within the stack
 182   bool sp_safe = (_SP <= thread->stack_base()) &&
 183                  (_SP >= thread->stack_base() - thread->stack_size());
 184 
 185   if (!sp_safe) {
 186     return false;
 187   }
 188 
 189   // unextended sp must be within the stack and above or equal sp
 190   bool unextended_sp_safe = (_UNEXTENDED_SP <= thread->stack_base()) &&
 191                             (_UNEXTENDED_SP >= _SP);
 192 
 193   if (!unextended_sp_safe) return false;
 194 
 195   // an fp must be within the stack and above (but not equal) sp
 196   bool fp_safe = (_FP <= thread->stack_base()) &&
 197                  (_FP > _SP);
 198 
 199   // We know sp/unextended_sp are safe only fp is questionable here
 200 
 201   // If the current frame is known to the code cache then we can attempt to
 202   // to construct the sender and do some validation of it. This goes a long way
 203   // toward eliminating issues when we get in frame construction code
 204 
 205   if (_cb != NULL ) {
 206 
 207     // First check if frame is complete and tester is reliable
 208     // Unfortunately we can only check frame complete for runtime stubs and nmethod
 209     // other generic buffer blobs are more problematic so we just assume they are
 210     // ok. adapter blobs never have a frame complete and are never ok.
 211 
 212     if (!_cb->is_frame_complete_at(_pc)) {
 213       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 214         return false;
 215       }
 216     }
 217 
 218     // Entry frame checks
 219     if (is_entry_frame()) {
 220       // an entry frame must have a valid fp.
 221 
 222       if (!fp_safe) {
 223         return false;
 224       }
 225 
 226       // Validate the JavaCallWrapper an entry frame must have
 227 
 228       address jcw = (address)entry_frame_call_wrapper();
 229 
 230       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > _FP);
 231 
 232       return jcw_safe;
 233 
 234     }
 235 
 236     intptr_t* younger_sp = sp();
 237     intptr_t* _SENDER_SP = sender_sp(); // sender is actually just _FP
 238     bool adjusted_stack = is_interpreted_frame();
 239 
 240     address   sender_pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 241 
 242 
 243     // We must always be able to find a recognizable pc
 244     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 245     if (sender_pc == NULL ||  sender_blob == NULL) {
 246       return false;
 247     }
 248 
 249     // It should be safe to construct the sender though it might not be valid
 250 
 251     frame sender(_SENDER_SP, younger_sp, adjusted_stack);
 252 
 253     // Do we have a valid fp?
 254     address sender_fp = (address) sender.fp();
 255 
 256     // an fp must be within the stack and above (but not equal) current frame's _FP
 257 
 258     bool sender_fp_safe = (sender_fp <= thread->stack_base()) &&
 259                    (sender_fp > _FP);
 260 
 261     if (!sender_fp_safe) {
 262       return false;
 263     }
 264 
 265 
 266     // If the potential sender is the interpreter then we can do some more checking
 267     if (Interpreter::contains(sender_pc)) {
 268       return sender.is_interpreted_frame_valid(thread);
 269     }
 270 
 271     // Could just be some random pointer within the codeBlob
 272     if (!sender.cb()->code_contains(sender_pc)) {
 273       return false;
 274     }
 275 
 276     // We should never be able to see an adapter if the current frame is something from code cache
 277     if (sender_blob->is_adapter_blob()) {
 278       return false;
 279     }
 280 
 281     if( sender.is_entry_frame()) {
 282       // Validate the JavaCallWrapper an entry frame must have
 283 
 284       address jcw = (address)sender.entry_frame_call_wrapper();
 285 
 286       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > sender_fp);
 287 
 288       return jcw_safe;
 289     }
 290 
 291     // If the frame size is 0 something is bad because every nmethod has a non-zero frame size
 292     // because you must allocate window space
 293 
 294     if (sender_blob->frame_size() == 0) {
 295       assert(!sender_blob->is_nmethod(), "should count return address at least");
 296       return false;
 297     }
 298 
 299     // The sender should positively be an nmethod or call_stub. On sparc we might in fact see something else.
 300     // The cause of this is because at a save instruction the O7 we get is a leftover from an earlier
 301     // window use. So if a runtime stub creates two frames (common in fastdebug/jvmg) then we see the
 302     // stale pc. So if the sender blob is not something we'd expect we have little choice but to declare
 303     // the stack unwalkable. pd_get_top_frame_for_signal_handler tries to recover from this by unwinding
 304     // that initial frame and retrying.
 305 
 306     if (!sender_blob->is_nmethod()) {
 307       return false;
 308     }
 309 
 310     // Could put some more validation for the potential non-interpreted sender
 311     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 312 
 313     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 314 
 315     // We've validated the potential sender that would be created
 316 
 317     return true;
 318 
 319   }
 320 
 321   // Must be native-compiled frame. Since sender will try and use fp to find
 322   // linkages it must be safe
 323 
 324   if (!fp_safe) return false;
 325 
 326   // could try and do some more potential verification of native frame if we could think of some...
 327 
 328   return true;
 329 }
 330 
 331 // constructors
 332 
 333 // Construct an unpatchable, deficient frame
 334 frame::frame(intptr_t* sp, unpatchable_t, address pc, CodeBlob* cb) {
 335 #ifdef _LP64
 336   assert( (((intptr_t)sp & (wordSize-1)) == 0), "frame constructor passed an invalid sp");
 337 #endif
 338   _sp = sp;
 339   _younger_sp = NULL;
 340   _pc = pc;
 341   _cb = cb;
 342   _sp_adjustment_by_callee = 0;
 343   assert(pc == NULL && cb == NULL || pc != NULL, "can't have a cb and no pc!");
 344   if (_cb == NULL && _pc != NULL ) {
 345     _cb = CodeCache::find_blob(_pc);
 346   }
 347   _deopt_state = unknown;
 348 #ifdef ASSERT
 349   if ( _cb != NULL && _cb->is_nmethod()) {
 350     // Without a valid unextended_sp() we can't convert the pc to "original"
 351     assert(!((nmethod*)_cb)->is_deopt_pc(_pc), "invariant broken");
 352   }
 353 #endif // ASSERT
 354 }
 355 
 356 frame::frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_is_interpreted) :
 357   _sp(sp),
 358   _younger_sp(younger_sp),
 359   _deopt_state(unknown),
 360   _sp_adjustment_by_callee(0) {
 361   if (younger_sp == NULL) {
 362     // make a deficient frame which doesn't know where its PC is
 363     _pc = NULL;
 364     _cb = NULL;
 365   } else {
 366     _pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 367     assert( (intptr_t*)younger_sp[FP->sp_offset_in_saved_window()] == (intptr_t*)((intptr_t)sp - STACK_BIAS), "younger_sp must be valid");
 368     // Any frame we ever build should always "safe" therefore we should not have to call
 369     // find_blob_unsafe
 370     // In case of native stubs, the pc retrieved here might be
 371     // wrong.  (the _last_native_pc will have the right value)
 372     // So do not put add any asserts on the _pc here.
 373   }
 374 
 375   if (_pc != NULL)
 376     _cb = CodeCache::find_blob(_pc);
 377 
 378   // Check for MethodHandle call sites.
 379   if (_cb != NULL) {
 380     nmethod* nm = _cb->as_nmethod_or_null();
 381     if (nm != NULL) {
 382       if (nm->is_deopt_mh_entry(_pc) || nm->is_method_handle_return(_pc)) {
 383         _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) sp[L7_mh_SP_save->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 384         // The SP is already adjusted by this MH call site, don't
 385         // overwrite this value with the wrong interpreter value.
 386         younger_frame_is_interpreted = false;
 387       }
 388     }
 389   }
 390 
 391   if (younger_frame_is_interpreted) {
 392     // compute adjustment to this frame's SP made by its interpreted callee
 393     _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) younger_sp[I5_savedSP->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 394   }
 395 
 396   // It is important that the frame is fully constructed when we do
 397   // this lookup as get_deopt_original_pc() needs a correct value for
 398   // unextended_sp() which uses _sp_adjustment_by_callee.
 399   if (_pc != NULL) {
 400     address original_pc = nmethod::get_deopt_original_pc(this);
 401     if (original_pc != NULL) {
 402       _pc = original_pc;
 403       _deopt_state = is_deoptimized;
 404     } else {
 405       _deopt_state = not_deoptimized;
 406     }
 407   }
 408 }
 409 
 410 bool frame::is_interpreted_frame() const  {
 411   return Interpreter::contains(pc());
 412 }
 413 
 414 // sender_sp
 415 
 416 intptr_t* frame::interpreter_frame_sender_sp() const {
 417   assert(is_interpreted_frame(), "interpreted frame expected");
 418   return fp();
 419 }
 420 
 421 #ifndef CC_INTERP
 422 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 423   assert(is_interpreted_frame(), "interpreted frame expected");
 424   Unimplemented();
 425 }
 426 #endif // CC_INTERP
 427 
 428 
 429 #ifdef ASSERT
 430 // Debugging aid
 431 static frame nth_sender(int n) {
 432   frame f = JavaThread::current()->last_frame();
 433 
 434   for(int i = 0; i < n; ++i)
 435     f = f.sender((RegisterMap*)NULL);
 436 
 437   printf("first frame %d\n",          f.is_first_frame()       ? 1 : 0);
 438   printf("interpreted frame %d\n",    f.is_interpreted_frame() ? 1 : 0);
 439   printf("java frame %d\n",           f.is_java_frame()        ? 1 : 0);
 440   printf("entry frame %d\n",          f.is_entry_frame()       ? 1 : 0);
 441   printf("native frame %d\n",         f.is_native_frame()      ? 1 : 0);
 442   if (f.is_compiled_frame()) {
 443     if (f.is_deoptimized_frame())
 444       printf("deoptimized frame 1\n");
 445     else
 446       printf("compiled frame 1\n");
 447   }
 448 
 449   return f;
 450 }
 451 #endif
 452 
 453 
 454 frame frame::sender_for_entry_frame(RegisterMap *map) const {
 455   assert(map != NULL, "map must be set");
 456   // Java frame called from C; skip all C frames and return top C
 457   // frame of that chunk as the sender
 458   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 459   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 460   assert(jfa->last_Java_sp() > _sp, "must be above this frame on stack");
 461   intptr_t* last_Java_sp = jfa->last_Java_sp();
 462   // Since we are walking the stack now this nested anchor is obviously walkable
 463   // even if it wasn't when it was stacked.
 464   if (!jfa->walkable()) {
 465     // Capture _last_Java_pc (if needed) and mark anchor walkable.
 466     jfa->capture_last_Java_pc(_sp);
 467   }
 468   assert(jfa->last_Java_pc() != NULL, "No captured pc!");
 469   map->clear();
 470   map->make_integer_regs_unsaved();
 471   map->shift_window(last_Java_sp, NULL);
 472   assert(map->include_argument_oops(), "should be set by clear");
 473   return frame(last_Java_sp, frame::unpatchable, jfa->last_Java_pc());
 474 }
 475 
 476 frame frame::sender_for_interpreter_frame(RegisterMap *map) const {
 477   ShouldNotCallThis();
 478   return sender(map);
 479 }
 480 
 481 frame frame::sender_for_compiled_frame(RegisterMap *map) const {
 482   ShouldNotCallThis();
 483   return sender(map);
 484 }
 485 
 486 frame frame::sender(RegisterMap* map) const {
 487   assert(map != NULL, "map must be set");
 488 
 489   assert(CodeCache::find_blob_unsafe(_pc) == _cb, "inconsistent");
 490 
 491   // Default is not to follow arguments; update it accordingly below
 492   map->set_include_argument_oops(false);
 493 
 494   if (is_entry_frame()) return sender_for_entry_frame(map);
 495 
 496   intptr_t* younger_sp = sp();
 497   intptr_t* sp         = sender_sp();
 498 
 499   // Note:  The version of this operation on any platform with callee-save
 500   //        registers must update the register map (if not null).
 501   //        In order to do this correctly, the various subtypes of
 502   //        of frame (interpreted, compiled, glue, native),
 503   //        must be distinguished.  There is no need on SPARC for
 504   //        such distinctions, because all callee-save registers are
 505   //        preserved for all frames via SPARC-specific mechanisms.
 506   //
 507   //        *** HOWEVER, *** if and when we make any floating-point
 508   //        registers callee-saved, then we will have to copy over
 509   //        the RegisterMap update logic from the Intel code.
 510 
 511   // The constructor of the sender must know whether this frame is interpreted so it can set the
 512   // sender's _sp_adjustment_by_callee field.  An osr adapter frame was originally
 513   // interpreted but its pc is in the code cache (for c1 -> osr_frame_return_id stub), so it must be
 514   // explicitly recognized.
 515 
 516   if (is_ricochet_frame())    return sender_for_ricochet_frame(map);
 517 
 518   bool frame_is_interpreted = is_interpreted_frame();
 519   if (frame_is_interpreted) {
 520     map->make_integer_regs_unsaved();
 521     map->shift_window(sp, younger_sp);
 522   } else if (_cb != NULL) {
 523     // Update the locations of implicitly saved registers to be their
 524     // addresses in the register save area.
 525     // For %o registers, the addresses of %i registers in the next younger
 526     // frame are used.
 527     map->shift_window(sp, younger_sp);
 528     if (map->update_map()) {
 529       // Tell GC to use argument oopmaps for some runtime stubs that need it.
 530       // For C1, the runtime stub might not have oop maps, so set this flag
 531       // outside of update_register_map.
 532       map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 533       if (_cb->oop_maps() != NULL) {
 534         OopMapSet::update_register_map(this, map);
 535       }
 536     }
 537   }
 538   return frame(sp, younger_sp, frame_is_interpreted);
 539 }
 540 
 541 
 542 void frame::patch_pc(Thread* thread, address pc) {
 543   if(thread == Thread::current()) {
 544    StubRoutines::Sparc::flush_callers_register_windows_func()();
 545   }
 546   if (TracePcPatching) {
 547     // QQQ this assert is invalid (or too strong anyway) sice _pc could
 548     // be original pc and frame could have the deopt pc.
 549     // assert(_pc == *O7_addr() + pc_return_offset, "frame has wrong pc");
 550     tty->print_cr("patch_pc at address  0x%x [0x%x -> 0x%x] ", O7_addr(), _pc, pc);
 551   }
 552   _cb = CodeCache::find_blob(pc);
 553   *O7_addr() = pc - pc_return_offset;
 554   _cb = CodeCache::find_blob(_pc);
 555   address original_pc = nmethod::get_deopt_original_pc(this);
 556   if (original_pc != NULL) {
 557     assert(original_pc == _pc, "expected original to be stored before patching");
 558     _deopt_state = is_deoptimized;
 559   } else {
 560     _deopt_state = not_deoptimized;
 561   }
 562 }
 563 
 564 
 565 static bool sp_is_valid(intptr_t* old_sp, intptr_t* young_sp, intptr_t* sp) {
 566   return (((intptr_t)sp & (2*wordSize-1)) == 0 &&
 567           sp <= old_sp &&
 568           sp >= young_sp);
 569 }
 570 
 571 
 572 /*
 573   Find the (biased) sp that is just younger than old_sp starting at sp.
 574   If not found return NULL. Register windows are assumed to be flushed.
 575 */
 576 intptr_t* frame::next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp) {
 577 
 578   intptr_t* previous_sp = NULL;
 579   intptr_t* orig_sp = sp;
 580 
 581   int max_frames = (old_sp - sp) / 16; // Minimum frame size is 16
 582   int max_frame2 = max_frames;
 583   while(sp != old_sp && sp_is_valid(old_sp, orig_sp, sp)) {
 584     if (max_frames-- <= 0)
 585       // too many frames have gone by; invalid parameters given to this function
 586       break;
 587     previous_sp = sp;
 588     sp = (intptr_t*)sp[FP->sp_offset_in_saved_window()];
 589     sp = (intptr_t*)((intptr_t)sp + STACK_BIAS);
 590   }
 591 
 592   return (sp == old_sp ? previous_sp : NULL);
 593 }
 594 
 595 /*
 596   Determine if "sp" is a valid stack pointer. "sp" is assumed to be younger than
 597   "valid_sp". So if "sp" is valid itself then it should be possible to walk frames
 598   from "sp" to "valid_sp". The assumption is that the registers windows for the
 599   thread stack in question are flushed.
 600 */
 601 bool frame::is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp) {
 602   return next_younger_sp_or_null(valid_sp, sp) != NULL;
 603 }
 604 
 605 
 606 bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {
 607   assert(is_interpreted_frame(), "must be interpreter frame");
 608   return this->fp() == fp;
 609 }
 610 
 611 
 612 void frame::pd_gc_epilog() {
 613   if (is_interpreted_frame()) {
 614     // set constant pool cache entry for interpreter
 615     methodOop m = interpreter_frame_method();
 616 
 617     *interpreter_frame_cpoolcache_addr() = m->constants()->cache();
 618   }
 619 }
 620 
 621 
 622 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 623 #ifdef CC_INTERP
 624   // Is there anything to do?
 625 #else
 626   assert(is_interpreted_frame(), "Not an interpreted frame");
 627   // These are reasonable sanity checks
 628   if (fp() == 0 || (intptr_t(fp()) & (2*wordSize-1)) != 0) {
 629     return false;
 630   }
 631   if (sp() == 0 || (intptr_t(sp()) & (2*wordSize-1)) != 0) {
 632     return false;
 633   }
 634 
 635   const intptr_t interpreter_frame_initial_sp_offset = interpreter_frame_vm_local_words;
 636   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 637     return false;
 638   }
 639   // These are hacks to keep us out of trouble.
 640   // The problem with these is that they mask other problems
 641   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 642     return false;
 643   }
 644   // do some validation of frame elements
 645 
 646   // first the method
 647 
 648   methodOop m = *interpreter_frame_method_addr();
 649 
 650   // validate the method we'd find in this potential sender
 651   if (!Universe::heap()->is_valid_method(m)) return false;
 652 
 653   // stack frames shouldn't be much larger than max_stack elements
 654 
 655   if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 656     return false;
 657   }
 658 
 659   // validate bci/bcx
 660 
 661   intptr_t  bcx    = interpreter_frame_bcx();
 662   if (m->validate_bci_from_bcx(bcx) < 0) {
 663     return false;
 664   }
 665 
 666   // validate constantPoolCacheOop
 667 
 668   constantPoolCacheOop cp = *interpreter_frame_cache_addr();
 669 
 670   if (cp == NULL ||
 671       !Space::is_aligned(cp) ||
 672       !Universe::heap()->is_permanent((void*)cp)) return false;
 673 
 674   // validate locals
 675 
 676   address locals =  (address) *interpreter_frame_locals_addr();
 677 
 678   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 679 
 680   // We'd have to be pretty unlucky to be mislead at this point
 681 #endif /* CC_INTERP */
 682   return true;
 683 }
 684 
 685 
 686 // Windows have been flushed on entry (but not marked). Capture the pc that
 687 // is the return address to the frame that contains "sp" as its stack pointer.
 688 // This pc resides in the called of the frame corresponding to "sp".
 689 // As a side effect we mark this JavaFrameAnchor as having flushed the windows.
 690 // This side effect lets us mark stacked JavaFrameAnchors (stacked in the
 691 // call_helper) as flushed when we have flushed the windows for the most
 692 // recent (i.e. current) JavaFrameAnchor. This saves useless flushing calls
 693 // and lets us find the pc just once rather than multiple times as it did
 694 // in the bad old _post_Java_state days.
 695 //
 696 void JavaFrameAnchor::capture_last_Java_pc(intptr_t* sp) {
 697   if (last_Java_sp() != NULL && last_Java_pc() == NULL) {
 698     // try and find the sp just younger than _last_Java_sp
 699     intptr_t* _post_Java_sp = frame::next_younger_sp_or_null(last_Java_sp(), sp);
 700     // Really this should never fail otherwise VM call must have non-standard
 701     // frame linkage (bad) or stack is not properly flushed (worse).
 702     guarantee(_post_Java_sp != NULL, "bad stack!");
 703     _last_Java_pc = (address) _post_Java_sp[ I7->sp_offset_in_saved_window()] + frame::pc_return_offset;
 704 
 705   }
 706   set_window_flushed();
 707 }
 708 
 709 void JavaFrameAnchor::make_walkable(JavaThread* thread) {
 710   if (walkable()) return;
 711   // Eventually make an assert
 712   guarantee(Thread::current() == (Thread*)thread, "only current thread can flush its registers");
 713   // We always flush in case the profiler wants it but we won't mark
 714   // the windows as flushed unless we have a last_Java_frame
 715   intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 716   if (last_Java_sp() != NULL ) {
 717     capture_last_Java_pc(sp);
 718   }
 719 }
 720 
 721 intptr_t* frame::entry_frame_argument_at(int offset) const {
 722   // convert offset to index to deal with tsi
 723   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 724 
 725   intptr_t* LSP = (intptr_t*) sp()[Lentry_args->sp_offset_in_saved_window()];
 726   return &LSP[index+1];
 727 }
 728 
 729 
 730 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 731   assert(is_interpreted_frame(), "interpreted frame expected");
 732   methodOop method = interpreter_frame_method();
 733   BasicType type = method->result_type();
 734 
 735   if (method->is_native()) {
 736     // Prior to notifying the runtime of the method_exit the possible result
 737     // value is saved to l_scratch and d_scratch.
 738 
 739 #ifdef CC_INTERP
 740     interpreterState istate = get_interpreterState();
 741     intptr_t* l_scratch = (intptr_t*) &istate->_native_lresult;
 742     intptr_t* d_scratch = (intptr_t*) &istate->_native_fresult;
 743 #else /* CC_INTERP */
 744     intptr_t* l_scratch = fp() + interpreter_frame_l_scratch_fp_offset;
 745     intptr_t* d_scratch = fp() + interpreter_frame_d_scratch_fp_offset;
 746 #endif /* CC_INTERP */
 747 
 748     address l_addr = (address)l_scratch;
 749 #ifdef _LP64
 750     // On 64-bit the result for 1/8/16/32-bit result types is in the other
 751     // word half
 752     l_addr += wordSize/2;
 753 #endif
 754 
 755     switch (type) {
 756       case T_OBJECT:
 757       case T_ARRAY: {
 758 #ifdef CC_INTERP
 759         *oop_result = istate->_oop_temp;
 760 #else
 761         oop obj = (oop) at(interpreter_frame_oop_temp_offset);
 762         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 763         *oop_result = obj;
 764 #endif // CC_INTERP
 765         break;
 766       }
 767 
 768       case T_BOOLEAN : { jint* p = (jint*)l_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 769       case T_BYTE    : { jint* p = (jint*)l_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 770       case T_CHAR    : { jint* p = (jint*)l_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 771       case T_SHORT   : { jint* p = (jint*)l_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 772       case T_INT     : value_result->i = *(jint*)l_addr; break;
 773       case T_LONG    : value_result->j = *(jlong*)l_scratch; break;
 774       case T_FLOAT   : value_result->f = *(jfloat*)d_scratch; break;
 775       case T_DOUBLE  : value_result->d = *(jdouble*)d_scratch; break;
 776       case T_VOID    : /* Nothing to do */ break;
 777       default        : ShouldNotReachHere();
 778     }
 779   } else {
 780     intptr_t* tos_addr = interpreter_frame_tos_address();
 781 
 782     switch(type) {
 783       case T_OBJECT:
 784       case T_ARRAY: {
 785         oop obj = (oop)*tos_addr;
 786         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 787         *oop_result = obj;
 788         break;
 789       }
 790       case T_BOOLEAN : { jint* p = (jint*)tos_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 791       case T_BYTE    : { jint* p = (jint*)tos_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 792       case T_CHAR    : { jint* p = (jint*)tos_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 793       case T_SHORT   : { jint* p = (jint*)tos_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 794       case T_INT     : value_result->i = *(jint*)tos_addr; break;
 795       case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 796       case T_FLOAT   : value_result->f = *(jfloat*)tos_addr; break;
 797       case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 798       case T_VOID    : /* Nothing to do */ break;
 799       default        : ShouldNotReachHere();
 800     }
 801   };
 802 
 803   return type;
 804 }
 805 
 806 // Lesp pointer is one word lower than the top item on the stack.
 807 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 808   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize) - 1;
 809   return &interpreter_frame_tos_address()[index];
 810 }
 811 
 812 
 813 #ifdef ASSERT
 814 
 815 #define DESCRIBE_FP_OFFSET(name) \
 816   values.describe(frame_no, fp() + frame::name##_offset, #name)
 817 
 818 void frame::describe_pd(FrameValues& values, int frame_no) {
 819   for (int w = 0; w < frame::register_save_words; w++) {
 820     values.describe(frame_no, sp() + w, err_msg("register save area word %d", w), 1);
 821   }
 822 
 823   if (is_interpreted_frame()) {
 824     DESCRIBE_FP_OFFSET(interpreter_frame_d_scratch_fp);
 825     DESCRIBE_FP_OFFSET(interpreter_frame_l_scratch_fp);
 826     DESCRIBE_FP_OFFSET(interpreter_frame_padding);
 827     DESCRIBE_FP_OFFSET(interpreter_frame_oop_temp);
 828   }
 829 
 830   if (!is_compiled_frame()) {
 831     if (frame::callee_aggregate_return_pointer_words != 0) {
 832       values.describe(frame_no, sp() + frame::callee_aggregate_return_pointer_sp_offset, "callee_aggregate_return_pointer_word");
 833     }
 834     for (int w = 0; w < frame::callee_register_argument_save_area_words; w++) {
 835       values.describe(frame_no, sp() + frame::callee_register_argument_save_area_sp_offset + w,
 836                       err_msg("callee_register_argument_save_area_words %d", w));
 837     }
 838   }
 839 }
 840 
 841 #endif
 842 
 843 intptr_t *frame::initial_deoptimization_info() {
 844   // unused... but returns fp() to minimize changes
 845   return fp();
 846 }
 847