1 /*
   2  * Copyright (c) 1997, 2016, 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 "code/codeCache.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/signature.hpp"
  38 #include "runtime/stubCodeGenerator.hpp"
  39 #include "runtime/stubRoutines.hpp"
  40 #include "vmreg_sparc.inline.hpp"
  41 #ifdef COMPILER1
  42 #include "c1/c1_Runtime1.hpp"
  43 #include "runtime/vframeArray.hpp"
  44 #endif
  45 
  46 void RegisterMap::pd_clear() {
  47   if (_thread->has_last_Java_frame()) {
  48     frame fr = _thread->last_frame();
  49     _window = fr.sp();
  50   } else {
  51     _window = NULL;
  52   }
  53   _younger_window = NULL;
  54 }
  55 
  56 
  57 // Unified register numbering scheme: each 32-bits counts as a register
  58 // number, so all the V9 registers take 2 slots.
  59 const static int R_L_nums[] = {0+040,2+040,4+040,6+040,8+040,10+040,12+040,14+040};
  60 const static int R_I_nums[] = {0+060,2+060,4+060,6+060,8+060,10+060,12+060,14+060};
  61 const static int R_O_nums[] = {0+020,2+020,4+020,6+020,8+020,10+020,12+020,14+020};
  62 const static int R_G_nums[] = {0+000,2+000,4+000,6+000,8+000,10+000,12+000,14+000};
  63 static RegisterMap::LocationValidType bad_mask = 0;
  64 static RegisterMap::LocationValidType R_LIO_mask = 0;
  65 static bool register_map_inited = false;
  66 
  67 static void register_map_init() {
  68   if (!register_map_inited) {
  69     register_map_inited = true;
  70     int i;
  71     for (i = 0; i < 8; i++) {
  72       assert(R_L_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  73       assert(R_I_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  74       assert(R_O_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  75       assert(R_G_nums[i] < RegisterMap::location_valid_type_size, "in first chunk");
  76     }
  77 
  78     bad_mask |= (1LL << R_O_nums[6]); // SP
  79     bad_mask |= (1LL << R_O_nums[7]); // cPC
  80     bad_mask |= (1LL << R_I_nums[6]); // FP
  81     bad_mask |= (1LL << R_I_nums[7]); // rPC
  82     bad_mask |= (1LL << R_G_nums[2]); // TLS
  83     bad_mask |= (1LL << R_G_nums[7]); // reserved by libthread
  84 
  85     for (i = 0; i < 8; i++) {
  86       R_LIO_mask |= (1LL << R_L_nums[i]);
  87       R_LIO_mask |= (1LL << R_I_nums[i]);
  88       R_LIO_mask |= (1LL << R_O_nums[i]);
  89     }
  90   }
  91 }
  92 
  93 
  94 address RegisterMap::pd_location(VMReg regname) const {
  95   register_map_init();
  96 
  97   assert(regname->is_reg(), "sanity check");
  98   // Only the GPRs get handled this way
  99   if( !regname->is_Register())
 100     return NULL;
 101 
 102   // don't talk about bad registers
 103   if ((bad_mask & ((LocationValidType)1 << regname->value())) != 0) {
 104     return NULL;
 105   }
 106 
 107   // Convert to a GPR
 108   Register reg;
 109   int second_word = 0;
 110   // 32-bit registers for in, out and local
 111   if (!regname->is_concrete()) {
 112     // HMM ought to return NULL for any non-concrete (odd) vmreg
 113     // this all tied up in the fact we put out double oopMaps for
 114     // register locations. When that is fixed we'd will return NULL
 115     // (or assert here).
 116     reg = regname->prev()->as_Register();
 117 #ifdef _LP64
 118     second_word = sizeof(jint);
 119 #else
 120     return NULL;
 121 #endif // _LP64
 122   } else {
 123     reg = regname->as_Register();
 124   }
 125   if (reg->is_out()) {
 126     assert(_younger_window != NULL, "Younger window should be available");
 127     return second_word + (address)&_younger_window[reg->after_save()->sp_offset_in_saved_window()];
 128   }
 129   if (reg->is_local() || reg->is_in()) {
 130     assert(_window != NULL, "Window should be available");
 131     return second_word + (address)&_window[reg->sp_offset_in_saved_window()];
 132   }
 133   // Only the window'd GPRs get handled this way; not the globals.
 134   return NULL;
 135 }
 136 
 137 
 138 #ifdef ASSERT
 139 void RegisterMap::check_location_valid() {
 140   register_map_init();
 141   assert((_location_valid[0] & bad_mask) == 0, "cannot have special locations for SP,FP,TLS,etc.");
 142 }
 143 #endif
 144 
 145 // We are shifting windows.  That means we are moving all %i to %o,
 146 // getting rid of all current %l, and keeping all %g.  This is only
 147 // complicated if any of the location pointers for these are valid.
 148 // The normal case is that everything is in its standard register window
 149 // home, and _location_valid[0] is zero.  In that case, this routine
 150 // does exactly nothing.
 151 void RegisterMap::shift_individual_registers() {
 152   if (!update_map())  return;  // this only applies to maps with locations
 153   register_map_init();
 154   check_location_valid();
 155 
 156   LocationValidType lv = _location_valid[0];
 157   LocationValidType lv0 = lv;
 158 
 159   lv &= ~R_LIO_mask;  // clear %l, %o, %i regs
 160 
 161   // if we cleared some non-%g locations, we may have to do some shifting
 162   if (lv != lv0) {
 163     // copy %i0-%i5 to %o0-%o5, if they have special locations
 164     // This can happen in within stubs which spill argument registers
 165     // around a dynamic link operation, such as resolve_opt_virtual_call.
 166     for (int i = 0; i < 8; i++) {
 167       if (lv0 & (1LL << R_I_nums[i])) {
 168         _location[R_O_nums[i]] = _location[R_I_nums[i]];
 169         lv |=  (1LL << R_O_nums[i]);
 170       }
 171     }
 172   }
 173 
 174   _location_valid[0] = lv;
 175   check_location_valid();
 176 }
 177 
 178 bool frame::safe_for_sender(JavaThread *thread) {
 179 
 180   address _SP = (address) sp();
 181   address _FP = (address) fp();
 182   address _UNEXTENDED_SP = (address) unextended_sp();
 183   // sp must be within the stack
 184   bool sp_safe = (_SP <= thread->stack_base()) &&
 185                  (_SP >= thread->stack_base() - thread->stack_size());
 186 
 187   if (!sp_safe) {
 188     return false;
 189   }
 190 
 191   // unextended sp must be within the stack and above or equal sp
 192   bool unextended_sp_safe = (_UNEXTENDED_SP <= thread->stack_base()) &&
 193                             (_UNEXTENDED_SP >= _SP);
 194 
 195   if (!unextended_sp_safe) return false;
 196 
 197   // an fp must be within the stack and above (but not equal) sp
 198   bool fp_safe = (_FP <= thread->stack_base()) &&
 199                  (_FP > _SP);
 200 
 201   // We know sp/unextended_sp are safe only fp is questionable here
 202 
 203   // If the current frame is known to the code cache then we can attempt to
 204   // to construct the sender and do some validation of it. This goes a long way
 205   // toward eliminating issues when we get in frame construction code
 206 
 207   if (_cb != NULL ) {
 208 
 209     // First check if frame is complete and tester is reliable
 210     // Unfortunately we can only check frame complete for runtime stubs and nmethod
 211     // other generic buffer blobs are more problematic so we just assume they are
 212     // ok. adapter blobs never have a frame complete and are never ok.
 213 
 214     if (!_cb->is_frame_complete_at(_pc)) {
 215       if (_cb->is_compiled() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 216         return false;
 217       }
 218     }
 219 
 220     // Could just be some random pointer within the codeBlob
 221     if (!_cb->code_contains(_pc)) {
 222       return false;
 223     }
 224 
 225     // Entry frame checks
 226     if (is_entry_frame()) {
 227       // an entry frame must have a valid fp.
 228 
 229       if (!fp_safe) {
 230         return false;
 231       }
 232 
 233       // Validate the JavaCallWrapper an entry frame must have
 234 
 235       address jcw = (address)entry_frame_call_wrapper();
 236 
 237       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > _FP);
 238 
 239       return jcw_safe;
 240 
 241     }
 242 
 243     intptr_t* younger_sp = sp();
 244     intptr_t* _SENDER_SP = sender_sp(); // sender is actually just _FP
 245     bool adjusted_stack = is_interpreted_frame();
 246 
 247     address   sender_pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 248 
 249 
 250     // We must always be able to find a recognizable pc
 251     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
 252     if (sender_pc == NULL ||  sender_blob == NULL) {
 253       return false;
 254     }
 255 
 256     // Could be a zombie method
 257     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
 258       return false;
 259     }
 260 
 261     // It should be safe to construct the sender though it might not be valid
 262 
 263     frame sender(_SENDER_SP, younger_sp, adjusted_stack);
 264 
 265     // Do we have a valid fp?
 266     address sender_fp = (address) sender.fp();
 267 
 268     // an fp must be within the stack and above (but not equal) current frame's _FP
 269 
 270     bool sender_fp_safe = (sender_fp <= thread->stack_base()) &&
 271                    (sender_fp > _FP);
 272 
 273     if (!sender_fp_safe) {
 274       return false;
 275     }
 276 
 277 
 278     // If the potential sender is the interpreter then we can do some more checking
 279     if (Interpreter::contains(sender_pc)) {
 280       return sender.is_interpreted_frame_valid(thread);
 281     }
 282 
 283     // Could just be some random pointer within the codeBlob
 284     if (!sender.cb()->code_contains(sender_pc)) {
 285       return false;
 286     }
 287 
 288     // We should never be able to see an adapter if the current frame is something from code cache
 289     if (sender_blob->is_adapter_blob()) {
 290       return false;
 291     }
 292 
 293     if( sender.is_entry_frame()) {
 294       // Validate the JavaCallWrapper an entry frame must have
 295 
 296       address jcw = (address)sender.entry_frame_call_wrapper();
 297 
 298       bool jcw_safe = (jcw <= thread->stack_base()) && ( jcw > sender_fp);
 299 
 300       return jcw_safe;
 301     }
 302 
 303     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
 304     // because you must allocate window space
 305 
 306     if (sender_blob->frame_size() <= 0) {
 307       assert(!sender_blob->is_compiled(), "should count return address at least");
 308       return false;
 309     }
 310 
 311     // The sender should positively be an nmethod or call_stub. On sparc we might in fact see something else.
 312     // The cause of this is because at a save instruction the O7 we get is a leftover from an earlier
 313     // window use. So if a runtime stub creates two frames (common in fastdebug/debug) then we see the
 314     // stale pc. So if the sender blob is not something we'd expect we have little choice but to declare
 315     // the stack unwalkable. pd_get_top_frame_for_signal_handler tries to recover from this by unwinding
 316     // that initial frame and retrying.
 317 
 318     if (!sender_blob->is_compiled()) {
 319       return false;
 320     }
 321 
 322     // Could put some more validation for the potential non-interpreted sender
 323     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
 324 
 325     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
 326 
 327     // We've validated the potential sender that would be created
 328 
 329     return true;
 330 
 331   }
 332 
 333   // Must be native-compiled frame. Since sender will try and use fp to find
 334   // linkages it must be safe
 335 
 336   if (!fp_safe) return false;
 337 
 338   // could try and do some more potential verification of native frame if we could think of some...
 339 
 340   return true;
 341 }
 342 
 343 // constructors
 344 
 345 // Construct an unpatchable, deficient frame
 346 void frame::init(intptr_t* sp, address pc, CodeBlob* cb) {
 347 #ifdef _LP64
 348   assert( (((intptr_t)sp & (wordSize-1)) == 0), "frame constructor passed an invalid sp");
 349 #endif
 350   _sp = sp;
 351   _younger_sp = NULL;
 352   _pc = pc;
 353   _cb = cb;
 354   _sp_adjustment_by_callee = 0;
 355   assert(pc == NULL && cb == NULL || pc != NULL, "can't have a cb and no pc!");
 356   if (_cb == NULL && _pc != NULL ) {
 357     _cb = CodeCache::find_blob(_pc);
 358   }
 359   _deopt_state = unknown;
 360 #ifdef ASSERT
 361   if ( _cb != NULL && _cb->is_compiled()) {
 362     // Without a valid unextended_sp() we can't convert the pc to "original"
 363     assert(!((CompiledMethod*)_cb)->is_deopt_pc(_pc), "invariant broken");
 364   }
 365 #endif // ASSERT
 366 }
 367 
 368 frame::frame(intptr_t* sp, unpatchable_t, address pc, CodeBlob* cb) {
 369   init(sp, pc, cb);
 370 }
 371 
 372 frame::frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_is_interpreted) :
 373   _sp(sp),
 374   _younger_sp(younger_sp),
 375   _deopt_state(unknown),
 376   _sp_adjustment_by_callee(0) {
 377   if (younger_sp == NULL) {
 378     // make a deficient frame which doesn't know where its PC is
 379     _pc = NULL;
 380     _cb = NULL;
 381   } else {
 382     _pc = (address)younger_sp[I7->sp_offset_in_saved_window()] + pc_return_offset;
 383     assert( (intptr_t*)younger_sp[FP->sp_offset_in_saved_window()] == (intptr_t*)((intptr_t)sp - STACK_BIAS), "younger_sp must be valid");
 384     // Any frame we ever build should always "safe" therefore we should not have to call
 385     // find_blob_unsafe
 386     // In case of native stubs, the pc retrieved here might be
 387     // wrong.  (the _last_native_pc will have the right value)
 388     // So do not put add any asserts on the _pc here.
 389   }
 390 
 391   if (_pc != NULL)
 392     _cb = CodeCache::find_blob(_pc);
 393 
 394   // Check for MethodHandle call sites.
 395   if (_cb != NULL) {
 396     CompiledMethod* nm = _cb->as_compiled_method_or_null();
 397     if (nm != NULL) {
 398       if (nm->is_deopt_mh_entry(_pc) || nm->is_method_handle_return(_pc)) {
 399         _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) sp[L7_mh_SP_save->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 400         // The SP is already adjusted by this MH call site, don't
 401         // overwrite this value with the wrong interpreter value.
 402         younger_frame_is_interpreted = false;
 403       }
 404     }
 405   }
 406 
 407   if (younger_frame_is_interpreted) {
 408     // compute adjustment to this frame's SP made by its interpreted callee
 409     _sp_adjustment_by_callee = (intptr_t*) ((intptr_t) younger_sp[I5_savedSP->sp_offset_in_saved_window()] + STACK_BIAS) - sp;
 410   }
 411 
 412   // It is important that the frame is fully constructed when we do
 413   // this lookup as get_deopt_original_pc() needs a correct value for
 414   // unextended_sp() which uses _sp_adjustment_by_callee.
 415   if (_pc != NULL) {
 416     address original_pc = CompiledMethod::get_deopt_original_pc(this);
 417     if (original_pc != NULL) {
 418       _pc = original_pc;
 419       _deopt_state = is_deoptimized;
 420     } else {
 421       _deopt_state = not_deoptimized;
 422     }
 423   }
 424 }
 425 
 426 #ifndef PRODUCT
 427 // This is a generic constructor which is only used by pns() in debug.cpp.
 428 frame::frame(void* sp, void* fp, void* pc) {
 429   init((intptr_t*)sp, (address)pc, NULL);
 430 }
 431 #endif
 432 
 433 bool frame::is_interpreted_frame() const  {
 434   return Interpreter::contains(pc());
 435 }
 436 
 437 // sender_sp
 438 
 439 intptr_t* frame::interpreter_frame_sender_sp() const {
 440   assert(is_interpreted_frame(), "interpreted frame expected");
 441   return fp();
 442 }
 443 
 444 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
 445   assert(is_interpreted_frame(), "interpreted frame expected");
 446   Unimplemented();
 447 }
 448 
 449 frame frame::sender_for_entry_frame(RegisterMap *map) const {
 450   assert(map != NULL, "map must be set");
 451   // Java frame called from C; skip all C frames and return top C
 452   // frame of that chunk as the sender
 453   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
 454   assert(!entry_frame_is_first(), "next Java fp must be non zero");
 455   assert(jfa->last_Java_sp() > _sp, "must be above this frame on stack");
 456   intptr_t* last_Java_sp = jfa->last_Java_sp();
 457   // Since we are walking the stack now this nested anchor is obviously walkable
 458   // even if it wasn't when it was stacked.
 459   if (!jfa->walkable()) {
 460     // Capture _last_Java_pc (if needed) and mark anchor walkable.
 461     jfa->capture_last_Java_pc(_sp);
 462   }
 463   assert(jfa->last_Java_pc() != NULL, "No captured pc!");
 464   map->clear();
 465   map->make_integer_regs_unsaved();
 466   map->shift_window(last_Java_sp, NULL);
 467   assert(map->include_argument_oops(), "should be set by clear");
 468   return frame(last_Java_sp, frame::unpatchable, jfa->last_Java_pc());
 469 }
 470 
 471 frame frame::sender_for_interpreter_frame(RegisterMap *map) const {
 472   ShouldNotCallThis();
 473   return sender(map);
 474 }
 475 
 476 frame frame::sender_for_compiled_frame(RegisterMap *map) const {
 477   ShouldNotCallThis();
 478   return sender(map);
 479 }
 480 
 481 frame frame::sender(RegisterMap* map) const {
 482   assert(map != NULL, "map must be set");
 483 
 484   assert(CodeCache::find_blob_unsafe(_pc) == _cb, "inconsistent");
 485 
 486   // Default is not to follow arguments; update it accordingly below
 487   map->set_include_argument_oops(false);
 488 
 489   if (is_entry_frame()) return sender_for_entry_frame(map);
 490 
 491   intptr_t* younger_sp = sp();
 492   intptr_t* sp         = sender_sp();
 493 
 494   // Note:  The version of this operation on any platform with callee-save
 495   //        registers must update the register map (if not null).
 496   //        In order to do this correctly, the various subtypes of
 497   //        of frame (interpreted, compiled, glue, native),
 498   //        must be distinguished.  There is no need on SPARC for
 499   //        such distinctions, because all callee-save registers are
 500   //        preserved for all frames via SPARC-specific mechanisms.
 501   //
 502   //        *** HOWEVER, *** if and when we make any floating-point
 503   //        registers callee-saved, then we will have to copy over
 504   //        the RegisterMap update logic from the Intel code.
 505 
 506   // The constructor of the sender must know whether this frame is interpreted so it can set the
 507   // sender's _sp_adjustment_by_callee field.  An osr adapter frame was originally
 508   // interpreted but its pc is in the code cache (for c1 -> osr_frame_return_id stub), so it must be
 509   // explicitly recognized.
 510 
 511 
 512   bool frame_is_interpreted = is_interpreted_frame();
 513   if (frame_is_interpreted) {
 514     map->make_integer_regs_unsaved();
 515     map->shift_window(sp, younger_sp);
 516   } else if (_cb != NULL) {
 517     // Update the locations of implicitly saved registers to be their
 518     // addresses in the register save area.
 519     // For %o registers, the addresses of %i registers in the next younger
 520     // frame are used.
 521     map->shift_window(sp, younger_sp);
 522     if (map->update_map()) {
 523       // Tell GC to use argument oopmaps for some runtime stubs that need it.
 524       // For C1, the runtime stub might not have oop maps, so set this flag
 525       // outside of update_register_map.
 526       map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
 527       if (_cb->oop_maps() != NULL) {
 528         OopMapSet::update_register_map(this, map);
 529       }
 530     }
 531   }
 532   return frame(sp, younger_sp, frame_is_interpreted);
 533 }
 534 
 535 
 536 void frame::patch_pc(Thread* thread, address pc) {
 537   if(thread == Thread::current()) {
 538    StubRoutines::Sparc::flush_callers_register_windows_func()();
 539   }
 540   if (TracePcPatching) {
 541     // QQQ this assert is invalid (or too strong anyway) sice _pc could
 542     // be original pc and frame could have the deopt pc.
 543     // assert(_pc == *O7_addr() + pc_return_offset, "frame has wrong pc");
 544     tty->print_cr("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
 545                   p2i(O7_addr()), p2i(_pc), p2i(pc));
 546   }
 547   _cb = CodeCache::find_blob(pc);
 548   *O7_addr() = pc - pc_return_offset;
 549   _cb = CodeCache::find_blob(_pc);
 550   address original_pc = CompiledMethod::get_deopt_original_pc(this);
 551   if (original_pc != NULL) {
 552     assert(original_pc == _pc, "expected original to be stored before patching");
 553     _deopt_state = is_deoptimized;
 554   } else {
 555     _deopt_state = not_deoptimized;
 556   }
 557 }
 558 
 559 
 560 static bool sp_is_valid(intptr_t* old_sp, intptr_t* young_sp, intptr_t* sp) {
 561   return (((intptr_t)sp & (2*wordSize-1)) == 0 &&
 562           sp <= old_sp &&
 563           sp >= young_sp);
 564 }
 565 
 566 
 567 /*
 568   Find the (biased) sp that is just younger than old_sp starting at sp.
 569   If not found return NULL. Register windows are assumed to be flushed.
 570 */
 571 intptr_t* frame::next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp) {
 572 
 573   intptr_t* previous_sp = NULL;
 574   intptr_t* orig_sp = sp;
 575 
 576   int max_frames = (old_sp - sp) / 16; // Minimum frame size is 16
 577   int max_frame2 = max_frames;
 578   while(sp != old_sp && sp_is_valid(old_sp, orig_sp, sp)) {
 579     if (max_frames-- <= 0)
 580       // too many frames have gone by; invalid parameters given to this function
 581       break;
 582     previous_sp = sp;
 583     sp = (intptr_t*)sp[FP->sp_offset_in_saved_window()];
 584     sp = (intptr_t*)((intptr_t)sp + STACK_BIAS);
 585   }
 586 
 587   return (sp == old_sp ? previous_sp : NULL);
 588 }
 589 
 590 /*
 591   Determine if "sp" is a valid stack pointer. "sp" is assumed to be younger than
 592   "valid_sp". So if "sp" is valid itself then it should be possible to walk frames
 593   from "sp" to "valid_sp". The assumption is that the registers windows for the
 594   thread stack in question are flushed.
 595 */
 596 bool frame::is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp) {
 597   return next_younger_sp_or_null(valid_sp, sp) != NULL;
 598 }
 599 
 600 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
 601   assert(is_interpreted_frame(), "Not an interpreted frame");
 602   // These are reasonable sanity checks
 603   if (fp() == 0 || (intptr_t(fp()) & (2*wordSize-1)) != 0) {
 604     return false;
 605   }
 606   if (sp() == 0 || (intptr_t(sp()) & (2*wordSize-1)) != 0) {
 607     return false;
 608   }
 609 
 610   const intptr_t interpreter_frame_initial_sp_offset = interpreter_frame_vm_local_words;
 611   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
 612     return false;
 613   }
 614   // These are hacks to keep us out of trouble.
 615   // The problem with these is that they mask other problems
 616   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
 617     return false;
 618   }
 619   // do some validation of frame elements
 620 
 621   // first the method
 622 
 623   Method* m = *interpreter_frame_method_addr();
 624 
 625   // validate the method we'd find in this potential sender
 626   if (!m->is_valid_method()) return false;
 627 
 628   // stack frames shouldn't be much larger than max_stack elements
 629 
 630   if (fp() - unextended_sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
 631     return false;
 632   }
 633 
 634   // validate bci/bcp
 635 
 636   address bcp = interpreter_frame_bcp();
 637   if (m->validate_bci_from_bcp(bcp) < 0) {
 638     return false;
 639   }
 640 
 641   // validate ConstantPoolCache*
 642   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
 643   if (cp == NULL || !cp->is_metaspace_object()) return false;
 644 
 645   // validate locals
 646 
 647   address locals =  (address) *interpreter_frame_locals_addr();
 648 
 649   if (locals > thread->stack_base() || locals < (address) fp()) return false;
 650 
 651   // We'd have to be pretty unlucky to be mislead at this point
 652   return true;
 653 }
 654 
 655 
 656 // Windows have been flushed on entry (but not marked). Capture the pc that
 657 // is the return address to the frame that contains "sp" as its stack pointer.
 658 // This pc resides in the called of the frame corresponding to "sp".
 659 // As a side effect we mark this JavaFrameAnchor as having flushed the windows.
 660 // This side effect lets us mark stacked JavaFrameAnchors (stacked in the
 661 // call_helper) as flushed when we have flushed the windows for the most
 662 // recent (i.e. current) JavaFrameAnchor. This saves useless flushing calls
 663 // and lets us find the pc just once rather than multiple times as it did
 664 // in the bad old _post_Java_state days.
 665 //
 666 void JavaFrameAnchor::capture_last_Java_pc(intptr_t* sp) {
 667   if (last_Java_sp() != NULL && last_Java_pc() == NULL) {
 668     // try and find the sp just younger than _last_Java_sp
 669     intptr_t* _post_Java_sp = frame::next_younger_sp_or_null(last_Java_sp(), sp);
 670     // Really this should never fail otherwise VM call must have non-standard
 671     // frame linkage (bad) or stack is not properly flushed (worse).
 672     guarantee(_post_Java_sp != NULL, "bad stack!");
 673     _last_Java_pc = (address) _post_Java_sp[ I7->sp_offset_in_saved_window()] + frame::pc_return_offset;
 674 
 675   }
 676   set_window_flushed();
 677 }
 678 
 679 void JavaFrameAnchor::make_walkable(JavaThread* thread) {
 680   if (walkable()) return;
 681   // Eventually make an assert
 682   guarantee(Thread::current() == (Thread*)thread, "only current thread can flush its registers");
 683   // We always flush in case the profiler wants it but we won't mark
 684   // the windows as flushed unless we have a last_Java_frame
 685   intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 686   if (last_Java_sp() != NULL ) {
 687     capture_last_Java_pc(sp);
 688   }
 689 }
 690 
 691 intptr_t* frame::entry_frame_argument_at(int offset) const {
 692   // convert offset to index to deal with tsi
 693   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
 694 
 695   intptr_t* LSP = (intptr_t*) sp()[Lentry_args->sp_offset_in_saved_window()];
 696   return &LSP[index+1];
 697 }
 698 
 699 
 700 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
 701   assert(is_interpreted_frame(), "interpreted frame expected");
 702   Method* method = interpreter_frame_method();
 703   BasicType type = method->result_type();
 704 
 705   if (method->is_native()) {
 706     // Prior to notifying the runtime of the method_exit the possible result
 707     // value is saved to l_scratch and d_scratch.
 708 
 709     intptr_t* l_scratch = fp() + interpreter_frame_l_scratch_fp_offset;
 710     intptr_t* d_scratch = fp() + interpreter_frame_d_scratch_fp_offset;
 711 
 712     address l_addr = (address)l_scratch;
 713 #ifdef _LP64
 714     // On 64-bit the result for 1/8/16/32-bit result types is in the other
 715     // word half
 716     l_addr += wordSize/2;
 717 #endif
 718 
 719     switch (type) {
 720       case T_OBJECT:
 721       case T_ARRAY: {
 722         oop obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
 723         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 724         *oop_result = obj;
 725         break;
 726       }
 727 
 728       case T_BOOLEAN : { jint* p = (jint*)l_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 729       case T_BYTE    : { jint* p = (jint*)l_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 730       case T_CHAR    : { jint* p = (jint*)l_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 731       case T_SHORT   : { jint* p = (jint*)l_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 732       case T_INT     : value_result->i = *(jint*)l_addr; break;
 733       case T_LONG    : value_result->j = *(jlong*)l_scratch; break;
 734       case T_FLOAT   : value_result->f = *(jfloat*)d_scratch; break;
 735       case T_DOUBLE  : value_result->d = *(jdouble*)d_scratch; break;
 736       case T_VOID    : /* Nothing to do */ break;
 737       default        : ShouldNotReachHere();
 738     }
 739   } else {
 740     intptr_t* tos_addr = interpreter_frame_tos_address();
 741 
 742     switch(type) {
 743       case T_OBJECT:
 744       case T_ARRAY: {
 745         oop obj = cast_to_oop(*tos_addr);
 746         assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
 747         *oop_result = obj;
 748         break;
 749       }
 750       case T_BOOLEAN : { jint* p = (jint*)tos_addr; value_result->z = (jboolean)((*p) & 0x1); break; }
 751       case T_BYTE    : { jint* p = (jint*)tos_addr; value_result->b = (jbyte)((*p) & 0xff); break; }
 752       case T_CHAR    : { jint* p = (jint*)tos_addr; value_result->c = (jchar)((*p) & 0xffff); break; }
 753       case T_SHORT   : { jint* p = (jint*)tos_addr; value_result->s = (jshort)((*p) & 0xffff); break; }
 754       case T_INT     : value_result->i = *(jint*)tos_addr; break;
 755       case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
 756       case T_FLOAT   : value_result->f = *(jfloat*)tos_addr; break;
 757       case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
 758       case T_VOID    : /* Nothing to do */ break;
 759       default        : ShouldNotReachHere();
 760     }
 761   };
 762 
 763   return type;
 764 }
 765 
 766 // Lesp pointer is one word lower than the top item on the stack.
 767 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
 768   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize) - 1;
 769   return &interpreter_frame_tos_address()[index];
 770 }
 771 
 772 
 773 #ifndef PRODUCT
 774 
 775 #define DESCRIBE_FP_OFFSET(name) \
 776   values.describe(frame_no, fp() + frame::name##_offset, #name)
 777 
 778 void frame::describe_pd(FrameValues& values, int frame_no) {
 779   for (int w = 0; w < frame::register_save_words; w++) {
 780     values.describe(frame_no, sp() + w, err_msg("register save area word %d", w), 1);
 781   }
 782 
 783   if (is_interpreted_frame()) {
 784     DESCRIBE_FP_OFFSET(interpreter_frame_d_scratch_fp);
 785     DESCRIBE_FP_OFFSET(interpreter_frame_l_scratch_fp);
 786     DESCRIBE_FP_OFFSET(interpreter_frame_mirror);
 787     DESCRIBE_FP_OFFSET(interpreter_frame_oop_temp);
 788 
 789     // esp, according to Lesp (e.g. not depending on bci), if seems valid
 790     intptr_t* esp = *interpreter_frame_esp_addr();
 791     if ((esp >= sp()) && (esp < fp())) {
 792       values.describe(-1, esp, "*Lesp");
 793     }
 794   }
 795 
 796   if (!is_compiled_frame()) {
 797     if (frame::callee_aggregate_return_pointer_words != 0) {
 798       values.describe(frame_no, sp() + frame::callee_aggregate_return_pointer_sp_offset, "callee_aggregate_return_pointer_word");
 799     }
 800     for (int w = 0; w < frame::callee_register_argument_save_area_words; w++) {
 801       values.describe(frame_no, sp() + frame::callee_register_argument_save_area_sp_offset + w,
 802                       err_msg("callee_register_argument_save_area_words %d", w));
 803     }
 804   }
 805 }
 806 
 807 #endif
 808 
 809 intptr_t *frame::initial_deoptimization_info() {
 810   // unused... but returns fp() to minimize changes introduced by 7087445
 811   return fp();
 812 }