1 /*
   2  * Copyright (c) 1997, 2013, 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/method.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "prims/methodHandles.hpp"
  32 #include "runtime/frame.inline.hpp"
  33 #include "runtime/handles.inline.hpp"
  34 #include "runtime/javaCalls.hpp"
  35 #include "runtime/monitorChunk.hpp"
  36 #include "runtime/signature.hpp"
  37 #include "runtime/stubCodeGenerator.hpp"
  38 #include "runtime/stubRoutines.hpp"
  39 #include "vmreg_sparc.inline.hpp"
  40 #ifdef COMPILER1
  41 #include "c1/c1_Runtime1.hpp"
  42 #include "runtime/vframeArray.hpp"
  43 #endif
  44 
  45 void RegisterMap::pd_clear() {
  46   if (_thread->has_last_Java_frame()) {
  47     frame fr = _thread->last_frame();
  48     _window = fr.sp();
  49   } else {
  50     _window = NULL;
  51   }
  52   _younger_window = NULL;
  53 }
  54 
  55 
  56 // Unified register numbering scheme: each 32-bits counts as a register
  57 // number, so all the V9 registers take 2 slots.
  58 const static int R_L_nums[] = {0+040,2+040,4+040,6+040,8+040,10+040,12+040,14+040};
  59 const static int R_I_nums[] = {0+060,2+060,4+060,6+060,8+060,10+060,12+060,14+060};
  60 const static int R_O_nums[] = {0+020,2+020,4+020,6+020,8+020,10+020,12+020,14+020};
  61 const static int R_G_nums[] = {0+000,2+000,4+000,6+000,8+000,10+000,12+000,14+000};
  62 static RegisterMap::LocationValidType bad_mask = 0;
  63 static RegisterMap::LocationValidType R_LIO_mask = 0;
  64 static bool register_map_inited = false;
  65 
  66 static void register_map_init() {
  67   if (!register_map_inited) {
  68     register_map_inited = true;
  69     int i;
  70     for (i = 0; i < 8; i++) {
  71       assert(R_L_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  72       assert(R_I_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  73       assert(R_O_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  74       assert(R_G_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  75     }
  76 
  77     bad_mask |= (1LL << R_O_nums[6]); // SP
  78     bad_mask |= (1LL << R_O_nums[7]); // cPC
  79     bad_mask |= (1LL << R_I_nums[6]); // FP
  80     bad_mask |= (1LL << R_I_nums[7]); // rPC
  81     bad_mask |= (1LL << R_G_nums[2]); // TLS
  82     bad_mask |= (1LL << R_G_nums[7]); // reserved by libthread
  83 
  84     for (i = 0; i < 8; i++) {
  85       R_LIO_mask |= (1LL << R_L_nums[i]);
  86       R_LIO_mask |= (1LL << R_I_nums[i]);
  87       R_LIO_mask |= (1LL << R_O_nums[i]);
  88     }
  89   }
  90 }
  91 
  92 
  93 address RegisterMap::pd_location(VMReg regname) const {
  94   register_map_init();
  95 
  96   assert(regname->is_reg(), "sanity check");
  97   // Only the GPRs get handled this way
  98   if( !regname->is_Register())
  99     return NULL;
 100 
 101   // don't talk about bad registers
 102   if ((bad_mask & ((LocationValidType)1 << regname->value())) != 0) {
 103     return NULL;
 104   }
 105 
 106   // Convert to a GPR
 107   Register reg;
 108   int second_word = 0;
 109   // 32-bit registers for in, out and local
 110   if (!regname->is_concrete()) {
 111     // HMM ought to return NULL for any non-concrete (odd) vmreg
 112     // this all tied up in the fact we put out double oopMaps for
 113     // register locations. When that is fixed we'd will return NULL
 114     // (or assert here).
 115     reg = regname->prev()->as_Register();
 116 #ifdef _LP64
 117     second_word = sizeof(jint);
 118 #else
 119     return NULL;
 120 #endif // _LP64
 121   } else {
 122     reg = regname->as_Register();
 123   }
 124   if (reg->is_out()) {
 125     assert(_younger_window != NULL, "Younger window should be available");
 126     return second_word + (address)&_younger_window[reg->after_save()->sp_offset_in_saved_window()];
 127   }
 128   if (reg->is_local() || reg->is_in()) {
 129     assert(_window != NULL, "Window should be available");
 130     return second_word + (address)&_window[reg->sp_offset_in_saved_window()];
 131   }
 132   // Only the window'd GPRs get handled this way; not the globals.
 133   return NULL;
 134 }
 135 
 136 
 137 #ifdef ASSERT
 138 void RegisterMap::check_location_valid() {
 139   register_map_init();
 140   assert((_location_valid[0] & bad_mask) == 0, "cannot have special locations for SP,FP,TLS,etc.");
 141 }
 142 #endif
 143 
 144 // We are shifting windows.  That means we are moving all %i to %o,
 145 // getting rid of all current %l, and keeping all %g.  This is only
 146 // complicated if any of the location pointers for these are valid.
 147 // The normal case is that everything is in its standard register window
 148 // home, and _location_valid[0] is zero.  In that case, this routine
 149 // does exactly nothing.
 150 void RegisterMap::shift_individual_registers() {
 151   if (!update_map())  return;  // this only applies to maps with locations
 152   register_map_init();
 153   check_location_valid();
 154 
 155   LocationValidType lv = _location_valid[0];
 156   LocationValidType lv0 = lv;
 157 
 158   lv &= ~R_LIO_mask;  // clear %l, %o, %i regs
 159 
 160   // if we cleared some non-%g locations, we may have to do some shifting
 161   if (lv != lv0) {
 162     // copy %i0-%i5 to %o0-%o5, if they have special locations
 163     // This can happen in within stubs which spill argument registers
 164     // around a dynamic link operation, such as resolve_opt_virtual_call.
 165     for (int i = 0; i < 8; i++) {
 166       if (lv0 & (1LL << R_I_nums[i])) {
 167         _location[R_O_nums[i]] = _location[R_I_nums[i]];
 168         lv |=  (1LL << R_O_nums[i]);
 169       }
 170     }
 171   }
 172 
 173   _location_valid[0] = lv;
 174   check_location_valid();
 175 }
 176 
 177 bool frame::safe_for_sender(JavaThread *thread) {
 178 
 179   address _SP = (address) sp();
 180   address _FP = (address) fp();
 181   address _UNEXTENDED_SP = (address) unextended_sp();
 182   // sp must be within the stack
 183   bool sp_safe = (_SP <= thread->stack_base()) &&
 184                  (_SP >= thread->stack_base() - thread->stack_size());
 185 
 186   if (!sp_safe) {
 187     return false;
 188   }
 189 
 190   // unextended sp must be within the stack and above or equal sp
 191   bool unextended_sp_safe = (_UNEXTENDED_SP <= thread->stack_base()) &&
 192                             (_UNEXTENDED_SP >= _SP);
 193 
 194   if (!unextended_sp_safe) return false;
 195 
 196   // an fp must be within the stack and above (but not equal) sp
 197   bool fp_safe = (_FP <= thread->stack_base()) &&
 198                  (_FP > _SP);
 199 
 200   // We know sp/unextended_sp are safe only fp is questionable here
 201 
 202   // If the current frame is known to the code cache then we can attempt to
 203   // to construct the sender and do some validation of it. This goes a long way
 204   // toward eliminating issues when we get in frame construction code
 205 
 206   if (_cb != NULL ) {
 207 
 208     // First check if frame is complete and tester is reliable
 209     // Unfortunately we can only check frame complete for runtime stubs and nmethod
 210     // other generic buffer blobs are more problematic so we just assume they are
 211     // ok. adapter blobs never have a frame complete and are never ok.
 212 
 213     if (!_cb->is_frame_complete_at(_pc)) {
 214       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 215         return false;
 216       }
 217     }
 218 
 219     // Could just be some random pointer within the codeBlob
 220     if (!_cb->code_contains(_pc)) {
 221       return false;
 222     }
 223 
 224     // Entry frame checks
 225     if (is_entry_frame()) {
 226       // an entry frame must have a valid fp.
 227 
 228       if (!fp_safe) {
 229         return false;
 230       }
 231 
 232       // Validate the JavaCallWrapper an entry frame must have
 233 
 234       address jcw = (address)entry_frame_call_wrapper();
 235 
 236       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > _FP);
 237 
 238       return jcw_safe;
 239 
 240     }
 241 
 242     intptr_t* younger_sp = sp();
 243     intptr_t* _SENDER_SP = sender_sp(); // sender is actually just _FP
 244     bool adjusted_stack = is_interpreted_frame();
 245 
 246     address   sender_pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 247 
 248 
 249     // We must always be able to find a recognizable pc
 250     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 251     if (sender_pc == NULL ||  sender_blob == NULL) {
 252       return false;
 253     }
 254 
 255     // It should be safe to construct the sender though it might not be valid
 256 
 257     frame sender(_SENDER_SP, younger_sp, adjusted_stack);
 258 
 259     // Do we have a valid fp?
 260     address sender_fp = (address) sender.fp();
 261 
 262     // an fp must be within the stack and above (but not equal) current frame's _FP
 263 
 264     bool sender_fp_safe = (sender_fp <= thread->stack_base()) &&
 265                    (sender_fp > _FP);
 266 
 267     if (!sender_fp_safe) {
 268       return false;
 269     }
 270 
 271 
 272     // If the potential sender is the interpreter then we can do some more checking
 273     if (Interpreter::contains(sender_pc)) {
 274       return sender.is_interpreted_frame_valid(thread);
 275     }
 276 
 277     // Could just be some random pointer within the codeBlob
 278     if (!sender.cb()->code_contains(sender_pc)) {
 279       return false;
 280     }
 281 
 282     // We should never be able to see an adapter if the current frame is something from code cache
 283     if (sender_blob->is_adapter_blob()) {
 284       return false;
 285     }
 286 
 287     if( sender.is_entry_frame()) {
 288       // Validate the JavaCallWrapper an entry frame must have
 289 
 290       address jcw = (address)sender.entry_frame_call_wrapper();
 291 
 292       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > sender_fp);
 293 
 294       return jcw_safe;
 295     }
 296 
 297     // If the frame size is 0 something is bad because every nmethod has a non-zero frame size
 298     // because you must allocate window space
 299 
 300     if (sender_blob->frame_size() == 0) {
 301       assert(!sender_blob->is_nmethod(), "should count return address at least");
 302       return false;
 303     }
 304 
 305     // The sender should positively be an nmethod or call_stub. On sparc we might in fact see something else.
 306     // The cause of this is because at a save instruction the O7 we get is a leftover from an earlier
 307     // window use. So if a runtime stub creates two frames (common in fastdebug/debug/jvmg) then we see the
 308     // stale pc. So if the sender blob is not something we'd expect we have little choice but to declare
 309     // the stack unwalkable. pd_get_top_frame_for_signal_handler tries to recover from this by unwinding
 310     // that initial frame and retrying.
 311 
 312     if (!sender_blob->is_nmethod()) {
 313       return false;
 314     }
 315 
 316     // Could put some more validation for the potential non-interpreted sender
 317     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 318 
 319     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 320 
 321     // We've validated the potential sender that would be created
 322 
 323     return true;
 324 
 325   }
 326 
 327   // Must be native-compiled frame. Since sender will try and use fp to find
 328   // linkages it must be safe
 329 
 330   if (!fp_safe) return false;
 331 
 332   // could try and do some more potential verification of native frame if we could think of some...
 333 
 334   return true;
 335 }
 336 
 337 // constructors
 338 
 339 // Construct an unpatchable, deficient frame
 340 frame::frame(intptr_t* sp, unpatchable_t, address pc, CodeBlob* cb) {
 341 #ifdef _LP64
 342   assert( (((intptr_t)sp & (wordSize-1)) == 0), "frame constructor passed an invalid sp");
 343 #endif
 344   _sp = sp;
 345   _younger_sp = NULL;
 346   _pc = pc;
 347   _cb = cb;
 348   _sp_adjustment_by_callee = 0;
 349   assert(pc == NULL && cb == NULL || pc != NULL, "can't have a cb and no pc!");
 350   if (_cb == NULL && _pc != NULL ) {
 351     _cb = CodeCache::find_blob(_pc);
 352   }
 353   _deopt_state = unknown;
 354 #ifdef ASSERT
 355   if ( _cb != NULL && _cb->is_nmethod()) {
 356     // Without a valid unextended_sp() we can't convert the pc to "original"
 357     assert(!((nmethod*)_cb)->is_deopt_pc(_pc), "invariant broken");
 358   }
 359 #endif // ASSERT
 360 }
 361 
 362 frame::frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_is_interpreted) :
 363   _sp(sp),
 364   _younger_sp(younger_sp),
 365   _deopt_state(unknown),
 366   _sp_adjustment_by_callee(0) {
 367   if (younger_sp == NULL) {
 368     // make a deficient frame which doesn't know where its PC is
 369     _pc = NULL;
 370     _cb = NULL;
 371   } else {
 372     _pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 373     assert( (intptr_t*)younger_sp[FP->sp_offset_in_saved_window()] == (intptr_t*)((intptr_t)sp - STACK_BIAS), "younger_sp must be valid");
 374     // Any frame we ever build should always "safe" therefore we should not have to call
 375     // find_blob_unsafe
 376     // In case of native stubs, the pc retrieved here might be
 377     // wrong.  (the _last_native_pc will have the right value)
 378     // So do not put add any asserts on the _pc here.
 379   }
 380 
 381   if (_pc != NULL)
 382     _cb = CodeCache::find_blob(_pc);
 383 
 384   // Check for MethodHandle call sites.
 385   if (_cb != NULL) {
 386     nmethod* nm = _cb->as_nmethod_or_null();
 387     if (nm != NULL) {
 388       if (nm->is_deopt_mh_entry(_pc) || nm->is_method_handle_return(_pc)) {
 389         _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) sp[L7_mh_SP_save->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 390         // The SP is already adjusted by this MH call site, don't
 391         // overwrite this value with the wrong interpreter value.
 392         younger_frame_is_interpreted = false;
 393       }
 394     }
 395   }
 396 
 397   if (younger_frame_is_interpreted) {
 398     // compute adjustment to this frame's SP made by its interpreted callee
 399     _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) younger_sp[I5_savedSP->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 400   }
 401 
 402   // It is important that the frame is fully constructed when we do
 403   // this lookup as get_deopt_original_pc() needs a correct value for
 404   // unextended_sp() which uses _sp_adjustment_by_callee.
 405   if (_pc != NULL) {
 406     address original_pc = nmethod::get_deopt_original_pc(this);
 407     if (original_pc != NULL) {
 408       _pc = original_pc;
 409       _deopt_state = is_deoptimized;
 410     } else {
 411       _deopt_state = not_deoptimized;
 412     }
 413   }
 414 }
 415 
 416 bool frame::is_interpreted_frame() const  {
 417   return Interpreter::contains(pc());
 418 }
 419 
 420 // sender_sp
 421 
 422 intptr_t* frame::interpreter_frame_sender_sp() const {
 423   assert(is_interpreted_frame(), "interpreted frame expected");
 424   return fp();
 425 }
 426 
 427 #ifndef CC_INTERP
 428 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 429   assert(is_interpreted_frame(), "interpreted frame expected");
 430   Unimplemented();
 431 }
 432 #endif // CC_INTERP
 433 
 434 
 435 #ifdef ASSERT
 436 // Debugging aid
 437 static frame nth_sender(int n) {
 438   frame f = JavaThread::current()->last_frame();
 439 
 440   for(int i = 0; i < n; ++i)
 441     f = f.sender((RegisterMap*)NULL);
 442 
 443   printf("first frame %d\n",          f.is_first_frame()       ? 1 : 0);
 444   printf("interpreted frame %d\n",    f.is_interpreted_frame() ? 1 : 0);
 445   printf("java frame %d\n",           f.is_java_frame()        ? 1 : 0);
 446   printf("entry frame %d\n",          f.is_entry_frame()       ? 1 : 0);
 447   printf("native frame %d\n",         f.is_native_frame()      ? 1 : 0);
 448   if (f.is_compiled_frame()) {
 449     if (f.is_deoptimized_frame())
 450       printf("deoptimized frame 1\n");
 451     else
 452       printf("compiled frame 1\n");
 453   }
 454 
 455   return f;
 456 }
 457 #endif
 458 
 459 
 460 frame frame::sender_for_entry_frame(RegisterMap *map) const {
 461   assert(map != NULL, "map must be set");
 462   // Java frame called from C; skip all C frames and return top C
 463   // frame of that chunk as the sender
 464   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 465   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 466   assert(jfa->last_Java_sp() > _sp, "must be above this frame on stack");
 467   intptr_t* last_Java_sp = jfa->last_Java_sp();
 468   // Since we are walking the stack now this nested anchor is obviously walkable
 469   // even if it wasn't when it was stacked.
 470   if (!jfa->walkable()) {
 471     // Capture _last_Java_pc (if needed) and mark anchor walkable.
 472     jfa->capture_last_Java_pc(_sp);
 473   }
 474   assert(jfa->last_Java_pc() != NULL, "No captured pc!");
 475   map->clear();
 476   map->make_integer_regs_unsaved();
 477   map->shift_window(last_Java_sp, NULL);
 478   assert(map->include_argument_oops(), "should be set by clear");
 479   return frame(last_Java_sp, frame::unpatchable, jfa->last_Java_pc());
 480 }
 481 
 482 frame frame::sender_for_interpreter_frame(RegisterMap *map) const {
 483   ShouldNotCallThis();
 484   return sender(map);
 485 }
 486 
 487 frame frame::sender_for_compiled_frame(RegisterMap *map) const {
 488   ShouldNotCallThis();
 489   return sender(map);
 490 }
 491 
 492 frame frame::sender(RegisterMap* map) const {
 493   assert(map != NULL, "map must be set");
 494 
 495   assert(CodeCache::find_blob_unsafe(_pc) == _cb, "inconsistent");
 496 
 497   // Default is not to follow arguments; update it accordingly below
 498   map->set_include_argument_oops(false);
 499 
 500   if (is_entry_frame()) return sender_for_entry_frame(map);
 501 
 502   intptr_t* younger_sp = sp();
 503   intptr_t* sp         = sender_sp();
 504 
 505   // Note:  The version of this operation on any platform with callee-save
 506   //        registers must update the register map (if not null).
 507   //        In order to do this correctly, the various subtypes of
 508   //        of frame (interpreted, compiled, glue, native),
 509   //        must be distinguished.  There is no need on SPARC for
 510   //        such distinctions, because all callee-save registers are
 511   //        preserved for all frames via SPARC-specific mechanisms.
 512   //
 513   //        *** HOWEVER, *** if and when we make any floating-point
 514   //        registers callee-saved, then we will have to copy over
 515   //        the RegisterMap update logic from the Intel code.
 516 
 517   // The constructor of the sender must know whether this frame is interpreted so it can set the
 518   // sender's _sp_adjustment_by_callee field.  An osr adapter frame was originally
 519   // interpreted but its pc is in the code cache (for c1 -> osr_frame_return_id stub), so it must be
 520   // explicitly recognized.
 521 
 522 
 523   bool frame_is_interpreted = is_interpreted_frame();
 524   if (frame_is_interpreted) {
 525     map->make_integer_regs_unsaved();
 526     map->shift_window(sp, younger_sp);
 527   } else if (_cb != NULL) {
 528     // Update the locations of implicitly saved registers to be their
 529     // addresses in the register save area.
 530     // For %o registers, the addresses of %i registers in the next younger
 531     // frame are used.
 532     map->shift_window(sp, younger_sp);
 533     if (map->update_map()) {
 534       // Tell GC to use argument oopmaps for some runtime stubs that need it.
 535       // For C1, the runtime stub might not have oop maps, so set this flag
 536       // outside of update_register_map.
 537       map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 538       if (_cb->oop_maps() != NULL) {
 539         OopMapSet::update_register_map(this, map);
 540       }
 541     }
 542   }
 543   return frame(sp, younger_sp, frame_is_interpreted);
 544 }
 545 
 546 
 547 void frame::patch_pc(Thread* thread, address pc) {
 548   if(thread == Thread::current()) {
 549    StubRoutines::Sparc::flush_callers_register_windows_func()();
 550   }
 551   if (TracePcPatching) {
 552     // QQQ this assert is invalid (or too strong anyway) sice _pc could
 553     // be original pc and frame could have the deopt pc.
 554     // assert(_pc == *O7_addr() + pc_return_offset, "frame has wrong pc");
 555     tty->print_cr("patch_pc at address  0x%x [0x%x -> 0x%x] ", O7_addr(), _pc, pc);
 556   }
 557   _cb = CodeCache::find_blob(pc);
 558   *O7_addr() = pc - pc_return_offset;
 559   _cb = CodeCache::find_blob(_pc);
 560   address original_pc = nmethod::get_deopt_original_pc(this);
 561   if (original_pc != NULL) {
 562     assert(original_pc == _pc, "expected original to be stored before patching");
 563     _deopt_state = is_deoptimized;
 564   } else {
 565     _deopt_state = not_deoptimized;
 566   }
 567 }
 568 
 569 
 570 static bool sp_is_valid(intptr_t* old_sp, intptr_t* young_sp, intptr_t* sp) {
 571   return (((intptr_t)sp & (2*wordSize-1)) == 0 &&
 572           sp <= old_sp &&
 573           sp >= young_sp);
 574 }
 575 
 576 
 577 /*
 578   Find the (biased) sp that is just younger than old_sp starting at sp.
 579   If not found return NULL. Register windows are assumed to be flushed.
 580 */
 581 intptr_t* frame::next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp) {
 582 
 583   intptr_t* previous_sp = NULL;
 584   intptr_t* orig_sp = sp;
 585 
 586   int max_frames = (old_sp - sp) / 16; // Minimum frame size is 16
 587   int max_frame2 = max_frames;
 588   while(sp != old_sp && sp_is_valid(old_sp, orig_sp, sp)) {
 589     if (max_frames-- <= 0)
 590       // too many frames have gone by; invalid parameters given to this function
 591       break;
 592     previous_sp = sp;
 593     sp = (intptr_t*)sp[FP->sp_offset_in_saved_window()];
 594     sp = (intptr_t*)((intptr_t)sp + STACK_BIAS);
 595   }
 596 
 597   return (sp == old_sp ? previous_sp : NULL);
 598 }
 599 
 600 /*
 601   Determine if "sp" is a valid stack pointer. "sp" is assumed to be younger than
 602   "valid_sp". So if "sp" is valid itself then it should be possible to walk frames
 603   from "sp" to "valid_sp". The assumption is that the registers windows for the
 604   thread stack in question are flushed.
 605 */
 606 bool frame::is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp) {
 607   return next_younger_sp_or_null(valid_sp, sp) != NULL;
 608 }
 609 
 610 
 611 bool frame::interpreter_frame_equals_unpacked_fp(intptr_t* fp) {
 612   assert(is_interpreted_frame(), "must be interpreter frame");
 613   return this->fp() == fp;
 614 }
 615 
 616 
 617 void frame::pd_gc_epilog() {
 618   if (is_interpreted_frame()) {
 619     // set constant pool cache entry for interpreter
 620     Method* m = interpreter_frame_method();
 621 
 622     *interpreter_frame_cpoolcache_addr() = m->constants()->cache();
 623   }
 624 }
 625 
 626 
 627 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 628 #ifdef CC_INTERP
 629   // Is there anything to do?
 630 #else
 631   assert(is_interpreted_frame(), "Not an interpreted frame");
 632   // These are reasonable sanity checks
 633   if (fp() == 0 || (intptr_t(fp()) & (2*wordSize-1)) != 0) {
 634     return false;
 635   }
 636   if (sp() == 0 || (intptr_t(sp()) & (2*wordSize-1)) != 0) {
 637     return false;
 638   }
 639 
 640   const intptr_t interpreter_frame_initial_sp_offset = interpreter_frame_vm_local_words;
 641   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 642     return false;
 643   }
 644   // These are hacks to keep us out of trouble.
 645   // The problem with these is that they mask other problems
 646   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 647     return false;
 648   }
 649   // do some validation of frame elements
 650 
 651   // first the method
 652 
 653   Method* m = *interpreter_frame_method_addr();
 654 
 655   // validate the method we'd find in this potential sender
 656   if (!m->is_valid_method()) return false;
 657 
 658   // stack frames shouldn't be much larger than max_stack elements
 659 
 660   if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 661     return false;
 662   }
 663 
 664   // validate bci/bcx
 665 
 666   intptr_t  bcx    = interpreter_frame_bcx();
 667   if (m->validate_bci_from_bcx(bcx) < 0) {
 668     return false;
 669   }
 670 
 671   // validate ConstantPoolCache*
 672   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
 673   if (cp == NULL || !cp->is_metadata()) return false;
 674 
 675   // validate locals
 676 
 677   address locals =  (address) *interpreter_frame_locals_addr();
 678 
 679   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 680 
 681   // We'd have to be pretty unlucky to be mislead at this point
 682 #endif /* CC_INTERP */
 683   return true;
 684 }
 685 
 686 
 687 // Windows have been flushed on entry (but not marked). Capture the pc that
 688 // is the return address to the frame that contains "sp" as its stack pointer.
 689 // This pc resides in the called of the frame corresponding to "sp".
 690 // As a side effect we mark this JavaFrameAnchor as having flushed the windows.
 691 // This side effect lets us mark stacked JavaFrameAnchors (stacked in the
 692 // call_helper) as flushed when we have flushed the windows for the most
 693 // recent (i.e. current) JavaFrameAnchor. This saves useless flushing calls
 694 // and lets us find the pc just once rather than multiple times as it did
 695 // in the bad old _post_Java_state days.
 696 //
 697 void JavaFrameAnchor::capture_last_Java_pc(intptr_t* sp) {
 698   if (last_Java_sp() != NULL && last_Java_pc() == NULL) {
 699     // try and find the sp just younger than _last_Java_sp
 700     intptr_t* _post_Java_sp = frame::next_younger_sp_or_null(last_Java_sp(), sp);
 701     // Really this should never fail otherwise VM call must have non-standard
 702     // frame linkage (bad) or stack is not properly flushed (worse).
 703     guarantee(_post_Java_sp != NULL, "bad stack!");
 704     _last_Java_pc = (address) _post_Java_sp[ I7->sp_offset_in_saved_window()] + frame::pc_return_offset;
 705 
 706   }
 707   set_window_flushed();
 708 }
 709 
 710 void JavaFrameAnchor::make_walkable(JavaThread* thread) {
 711   if (walkable()) return;
 712   // Eventually make an assert
 713   guarantee(Thread::current() == (Thread*)thread, "only current thread can flush its registers");
 714   // We always flush in case the profiler wants it but we won't mark
 715   // the windows as flushed unless we have a last_Java_frame
 716   intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 717   if (last_Java_sp() != NULL ) {
 718     capture_last_Java_pc(sp);
 719   }
 720 }
 721 
 722 intptr_t* frame::entry_frame_argument_at(int offset) const {
 723   // convert offset to index to deal with tsi
 724   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 725 
 726   intptr_t* LSP = (intptr_t*) sp()[Lentry_args->sp_offset_in_saved_window()];
 727   return &LSP[index+1];
 728 }
 729 
 730 
 731 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 732   assert(is_interpreted_frame(), "interpreted frame expected");
 733   Method* method = interpreter_frame_method();
 734   BasicType type = method->result_type();
 735 
 736   if (method->is_native()) {
 737     // Prior to notifying the runtime of the method_exit the possible result
 738     // value is saved to l_scratch and d_scratch.
 739 
 740 #ifdef CC_INTERP
 741     interpreterState istate = get_interpreterState();
 742     intptr_t* l_scratch = (intptr_t*) &istate->_native_lresult;
 743     intptr_t* d_scratch = (intptr_t*) &istate->_native_fresult;
 744 #else /* CC_INTERP */
 745     intptr_t* l_scratch = fp() + interpreter_frame_l_scratch_fp_offset;
 746     intptr_t* d_scratch = fp() + interpreter_frame_d_scratch_fp_offset;
 747 #endif /* CC_INTERP */
 748 
 749     address l_addr = (address)l_scratch;
 750 #ifdef _LP64
 751     // On 64-bit the result for 1/8/16/32-bit result types is in the other
 752     // word half
 753     l_addr += wordSize/2;
 754 #endif
 755 
 756     switch (type) {
 757       case T_OBJECT:
 758       case T_ARRAY: {
 759 #ifdef CC_INTERP
 760         *oop_result = istate->_oop_temp;
 761 #else
 762         oop obj = (oop) at(interpreter_frame_oop_temp_offset);
 763         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 764         *oop_result = obj;
 765 #endif // CC_INTERP
 766         break;
 767       }
 768 
 769       case T_BOOLEAN : { jint* p = (jint*)l_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 770       case T_BYTE    : { jint* p = (jint*)l_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 771       case T_CHAR    : { jint* p = (jint*)l_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 772       case T_SHORT   : { jint* p = (jint*)l_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 773       case T_INT     : value_result->i = *(jint*)l_addr; break;
 774       case T_LONG    : value_result->j = *(jlong*)l_scratch; break;
 775       case T_FLOAT   : value_result->f = *(jfloat*)d_scratch; break;
 776       case T_DOUBLE  : value_result->d = *(jdouble*)d_scratch; break;
 777       case T_VOID    : /* Nothing to do */ break;
 778       default        : ShouldNotReachHere();
 779     }
 780   } else {
 781     intptr_t* tos_addr = interpreter_frame_tos_address();
 782 
 783     switch(type) {
 784       case T_OBJECT:
 785       case T_ARRAY: {
 786         oop obj = (oop)*tos_addr;
 787         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 788         *oop_result = obj;
 789         break;
 790       }
 791       case T_BOOLEAN : { jint* p = (jint*)tos_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 792       case T_BYTE    : { jint* p = (jint*)tos_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 793       case T_CHAR    : { jint* p = (jint*)tos_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 794       case T_SHORT   : { jint* p = (jint*)tos_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 795       case T_INT     : value_result->i = *(jint*)tos_addr; break;
 796       case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 797       case T_FLOAT   : value_result->f = *(jfloat*)tos_addr; break;
 798       case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 799       case T_VOID    : /* Nothing to do */ break;
 800       default        : ShouldNotReachHere();
 801     }
 802   };
 803 
 804   return type;
 805 }
 806 
 807 // Lesp pointer is one word lower than the top item on the stack.
 808 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 809   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize) - 1;
 810   return &interpreter_frame_tos_address()[index];
 811 }
 812 
 813 
 814 #ifndef PRODUCT
 815 
 816 #define DESCRIBE_FP_OFFSET(name) \
 817   values.describe(frame_no, fp() + frame::name##_offset, #name)
 818 
 819 void frame::describe_pd(FrameValues& values, int frame_no) {
 820   for (int w = 0; w < frame::register_save_words; w++) {
 821     values.describe(frame_no, sp() + w, err_msg("register save area word %d", w), 1);
 822   }
 823 
 824   if (is_interpreted_frame()) {
 825     DESCRIBE_FP_OFFSET(interpreter_frame_d_scratch_fp);
 826     DESCRIBE_FP_OFFSET(interpreter_frame_l_scratch_fp);
 827     DESCRIBE_FP_OFFSET(interpreter_frame_padding);
 828     DESCRIBE_FP_OFFSET(interpreter_frame_oop_temp);
 829 
 830     // esp, according to Lesp (e.g. not depending on bci), if seems valid
 831     intptr_t* esp = *interpreter_frame_esp_addr();
 832     if ((esp >= sp()) && (esp < fp())) {
 833       values.describe(-1, esp, "*Lesp");
 834     }
 835   }
 836 
 837   if (!is_compiled_frame()) {
 838     if (frame::callee_aggregate_return_pointer_words != 0) {
 839       values.describe(frame_no, sp() + frame::callee_aggregate_return_pointer_sp_offset, "callee_aggregate_return_pointer_word");
 840     }
 841     for (int w = 0; w < frame::callee_register_argument_save_area_words; w++) {
 842       values.describe(frame_no, sp() + frame::callee_register_argument_save_area_sp_offset + w,
 843                       err_msg("callee_register_argument_save_area_words %d", w));
 844     }
 845   }
 846 }
 847 
 848 #endif
 849 
 850 intptr_t *frame::initial_deoptimization_info() {
 851   // unused... but returns fp() to minimize changes introduced by 7087445
 852   return fp();
 853 }