1 /*
  2  * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
  3  * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved.
  4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  5  *
  6  * This code is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
  9  *
 10  * This code is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 13  * version 2 for more details (a copy is included in the LICENSE file that
 14  * accompanied this code).
 15  *
 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #include "precompiled.hpp"
 27 #include "compiler/oopMap.hpp"
 28 #include "interpreter/interpreter.hpp"
 29 #include "memory/resourceArea.hpp"
 30 #include "memory/universe.hpp"
 31 #include "oops/markWord.hpp"
 32 #include "oops/method.hpp"
 33 #include "oops/oop.inline.hpp"
 34 #include "prims/methodHandles.hpp"
 35 #include "runtime/frame.inline.hpp"
 36 #include "runtime/handles.inline.hpp"
 37 #include "runtime/javaCalls.hpp"
 38 #include "runtime/monitorChunk.hpp"
 39 #include "runtime/os.inline.hpp"
 40 #include "runtime/signature.hpp"
 41 #include "runtime/stackWatermarkSet.hpp"
 42 #include "runtime/stubCodeGenerator.hpp"
 43 #include "runtime/stubRoutines.hpp"
 44 #include "vmreg_aarch64.inline.hpp"
 45 #ifdef COMPILER1
 46 #include "c1/c1_Runtime1.hpp"
 47 #include "runtime/vframeArray.hpp"
 48 #endif
 49 
 50 #ifdef ASSERT
 51 void RegisterMap::check_location_valid() {
 52 }
 53 #endif
 54 
 55 
 56 // Profiling/safepoint support
 57 
 58 bool frame::safe_for_sender(JavaThread *thread) {
 59   address   sp = (address)_sp;
 60   address   fp = (address)_fp;
 61   address   unextended_sp = (address)_unextended_sp;
 62 
 63   // consider stack guards when trying to determine "safe" stack pointers
 64   // sp must be within the usable part of the stack (not in guards)
 65   if (!thread->is_in_usable_stack(sp)) {
 66     return false;
 67   }
 68 
 69   // When we are running interpreted code the machine stack pointer, SP, is
 70   // set low enough so that the Java expression stack can grow and shrink
 71   // without ever exceeding the machine stack bounds.  So, ESP >= SP.
 72 
 73   // When we call out of an interpreted method, SP is incremented so that
 74   // the space between SP and ESP is removed.  The SP saved in the callee's
 75   // frame is the SP *before* this increment.  So, when we walk a stack of
 76   // interpreter frames the sender's SP saved in a frame might be less than
 77   // the SP at the point of call.
 78 
 79   // So unextended sp must be within the stack but we need not to check
 80   // that unextended sp >= sp
 81   if (!thread->is_in_full_stack_checked(unextended_sp)) {
 82     return false;
 83   }
 84 
 85   // an fp must be within the stack and above (but not equal) sp
 86   // second evaluation on fp+ is added to handle situation where fp is -1
 87   bool fp_safe = thread->is_in_stack_range_excl(fp, sp) &&
 88                  thread->is_in_full_stack_checked(fp + (return_addr_offset * sizeof(void*)));
 89 
 90   // We know sp/unextended_sp are safe only fp is questionable here
 91 
 92   // If the current frame is known to the code cache then we can attempt to
 93   // to construct the sender and do some validation of it. This goes a long way
 94   // toward eliminating issues when we get in frame construction code
 95 
 96   if (_cb != NULL ) {
 97 
 98     // First check if frame is complete and tester is reliable
 99     // Unfortunately we can only check frame complete for runtime stubs and nmethod
100     // other generic buffer blobs are more problematic so we just assume they are
101     // ok. adapter blobs never have a frame complete and are never ok.
102 
103     if (!_cb->is_frame_complete_at(_pc)) {
104       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
105         return false;
106       }
107     }
108 
109     // Could just be some random pointer within the codeBlob
110     if (!_cb->code_contains(_pc)) {
111       return false;
112     }
113 
114     // Entry frame checks
115     if (is_entry_frame()) {
116       // an entry frame must have a valid fp.
117       return fp_safe && is_entry_frame_valid(thread);
118     }
119 
120     intptr_t* sender_sp = NULL;
121     intptr_t* sender_unextended_sp = NULL;
122     address   sender_pc = NULL;
123     intptr_t* saved_fp =  NULL;
124 
125     if (is_interpreted_frame()) {
126       // fp must be safe
127       if (!fp_safe) {
128         return false;
129       }
130 
131       // for interpreted frames, the value below is the sender "raw" sp,
132       // which can be different from the sender unextended sp (the sp seen
133       // by the sender) because of current frame local variables
134       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
135       sender_unextended_sp = (intptr_t*) this->fp()[interpreter_frame_sender_sp_offset];
136       saved_fp = (intptr_t*) this->fp()[link_offset];
137       sender_pc = pauth_strip_verifiable((address) this->fp()[return_addr_offset], (address)saved_fp);
138 
139     } else {
140       // must be some sort of compiled/runtime frame
141       // fp does not have to be safe (although it could be check for c1?)
142 
143       // check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
144       if (_cb->frame_size() <= 0) {
145         return false;
146       }
147 
148       sender_sp = _unextended_sp + _cb->frame_size();
149       // Is sender_sp safe?
150       if (!thread->is_in_full_stack_checked((address)sender_sp)) {
151         return false;
152       }
153       sender_unextended_sp = sender_sp;
154       // Note: frame::sender_sp_offset is only valid for compiled frame
155       saved_fp = (intptr_t*) *(sender_sp - frame::sender_sp_offset);
156       sender_pc = pauth_strip_verifiable((address) *(sender_sp-1), (address)saved_fp);
157     }
158 
159 
160     // If the potential sender is the interpreter then we can do some more checking
161     if (Interpreter::contains(sender_pc)) {
162 
163       // fp is always saved in a recognizable place in any code we generate. However
164       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved fp
165       // is really a frame pointer.
166 
167       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
168         return false;
169       }
170 
171       // construct the potential sender
172 
173       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
174 
175       return sender.is_interpreted_frame_valid(thread);
176 
177     }
178 
179     // We must always be able to find a recognizable pc
180     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
181     if (sender_pc == NULL ||  sender_blob == NULL) {
182       return false;
183     }
184 
185     // Could be a zombie method
186     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
187       return false;
188     }
189 
190     // Could just be some random pointer within the codeBlob
191     if (!sender_blob->code_contains(sender_pc)) {
192       return false;
193     }
194 
195     // We should never be able to see an adapter if the current frame is something from code cache
196     if (sender_blob->is_adapter_blob()) {
197       return false;
198     }
199 
200     // Could be the call_stub
201     if (StubRoutines::returns_to_call_stub(sender_pc)) {
202       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
203         return false;
204       }
205 
206       // construct the potential sender
207 
208       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
209 
210       // Validate the JavaCallWrapper an entry frame must have
211       address jcw = (address)sender.entry_frame_call_wrapper();
212 
213       return thread->is_in_stack_range_excl(jcw, (address)sender.fp());
214     }
215 
216     CompiledMethod* nm = sender_blob->as_compiled_method_or_null();
217     if (nm != NULL) {
218       if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc) ||
219           nm->method()->is_method_handle_intrinsic()) {
220         return false;
221       }
222     }
223 
224     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
225     // because the return address counts against the callee's frame.
226 
227     if (sender_blob->frame_size() <= 0) {
228       assert(!sender_blob->is_compiled(), "should count return address at least");
229       return false;
230     }
231 
232     // We should never be able to see anything here except an nmethod. If something in the
233     // code cache (current frame) is called by an entity within the code cache that entity
234     // should not be anything but the call stub (already covered), the interpreter (already covered)
235     // or an nmethod.
236 
237     if (!sender_blob->is_compiled()) {
238         return false;
239     }
240 
241     // Could put some more validation for the potential non-interpreted sender
242     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
243 
244     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
245 
246     // We've validated the potential sender that would be created
247     return true;
248   }
249 
250   // Must be native-compiled frame. Since sender will try and use fp to find
251   // linkages it must be safe
252 
253   if (!fp_safe) {
254     return false;
255   }
256 
257   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
258 
259   if ( (address) this->fp()[return_addr_offset] == NULL) return false;
260 
261 
262   // could try and do some more potential verification of native frame if we could think of some...
263 
264   return true;
265 
266 }
267 
268 void frame::patch_pc(Thread* thread, address pc) {
269   assert(_cb == CodeCache::find_blob(pc), "unexpected pc");
270   address* pc_addr = &(((address*) sp())[-1]);
271   address signing_sp = (((address*) sp())[-2]);
272   address signed_pc = pauth_sign_return_address(pc, (address)signing_sp);
273   address pc_old = pauth_strip_verifiable(*pc_addr, (address)signing_sp);
274   if (TracePcPatching) {
275     tty->print("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
276                   p2i(pc_addr), p2i(pc_old), p2i(pc));
277     if (VM_Version::use_rop_protection()) {
278       tty->print(" [signed " INTPTR_FORMAT " -> " INTPTR_FORMAT "]", p2i(*pc_addr), p2i(signed_pc));
279     }
280     tty->print_cr("");
281   }
282 
283   // Either the return address is the original one or we are going to
284   // patch in the same address that's already there.
285   assert(_pc == pc_old || pc == pc_old, "must be");
286   *pc_addr = signed_pc;
287   address original_pc = CompiledMethod::get_deopt_original_pc(this);
288   if (original_pc != NULL) {
289     assert(original_pc == _pc, "expected original PC to be stored before patching");
290     _deopt_state = is_deoptimized;
291     // leave _pc as is
292   } else {
293     _deopt_state = not_deoptimized;
294     _pc = pc;
295   }
296 }
297 
298 bool frame::is_interpreted_frame() const  {
299   return Interpreter::contains(pc());
300 }
301 
302 int frame::frame_size(RegisterMap* map) const {
303   frame sender = this->sender(map);
304   return sender.sp() - sp();
305 }
306 
307 intptr_t* frame::entry_frame_argument_at(int offset) const {
308   // convert offset to index to deal with tsi
309   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
310   // Entry frame's arguments are always in relation to unextended_sp()
311   return &unextended_sp()[index];
312 }
313 
314 // sender_sp
315 intptr_t* frame::interpreter_frame_sender_sp() const {
316   assert(is_interpreted_frame(), "interpreted frame expected");
317   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
318 }
319 
320 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
321   assert(is_interpreted_frame(), "interpreted frame expected");
322   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
323 }
324 
325 
326 // monitor elements
327 
328 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
329   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
330 }
331 
332 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
333   BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
334   // make sure the pointer points inside the frame
335   assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
336   assert((intptr_t*) result < fp(),  "monitor end should be strictly below the frame pointer");
337   return result;
338 }
339 
340 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
341   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
342 }
343 
344 // Used by template based interpreter deoptimization
345 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
346     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
347 }
348 
349 frame frame::sender_for_entry_frame(RegisterMap* map) const {
350   assert(map != NULL, "map must be set");
351   // Java frame called from C; skip all C frames and return top C
352   // frame of that chunk as the sender
353   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
354   assert(!entry_frame_is_first(), "next Java fp must be non zero");
355   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
356   // Since we are walking the stack now this nested anchor is obviously walkable
357   // even if it wasn't when it was stacked.
358   jfa->make_walkable();
359   map->clear();
360   assert(map->include_argument_oops(), "should be set by clear");
361   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
362   fr.set_sp_is_trusted();
363 
364   return fr;
365 }
366 
367 OptimizedEntryBlob::FrameData* OptimizedEntryBlob::frame_data_for_frame(const frame& frame) const {
368   ShouldNotCallThis();
369   return nullptr;
370 }
371 
372 bool frame::optimized_entry_frame_is_first() const {
373   ShouldNotCallThis();
374   return false;
375 }
376 
377 frame frame::sender_for_optimized_entry_frame(RegisterMap* map) const {
378   ShouldNotCallThis();
379   return {};
380 }
381 
382 //------------------------------------------------------------------------------
383 // frame::verify_deopt_original_pc
384 //
385 // Verifies the calculated original PC of a deoptimization PC for the
386 // given unextended SP.
387 #ifdef ASSERT
388 void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp) {
389   frame fr;
390 
391   // This is ugly but it's better than to change {get,set}_original_pc
392   // to take an SP value as argument.  And it's only a debugging
393   // method anyway.
394   fr._unextended_sp = unextended_sp;
395 
396   address original_pc = nm->get_original_pc(&fr);
397   assert(nm->insts_contains_inclusive(original_pc),
398          "original PC must be in the main code section of the the compiled method (or must be immediately following it)");
399 }
400 #endif
401 
402 //------------------------------------------------------------------------------
403 // frame::adjust_unextended_sp
404 void frame::adjust_unextended_sp() {
405   // On aarch64, sites calling method handle intrinsics and lambda forms are treated
406   // as any other call site. Therefore, no special action is needed when we are
407   // returning to any of these call sites.
408 
409   if (_cb != NULL) {
410     CompiledMethod* sender_cm = _cb->as_compiled_method_or_null();
411     if (sender_cm != NULL) {
412       // If the sender PC is a deoptimization point, get the original PC.
413       if (sender_cm->is_deopt_entry(_pc) ||
414           sender_cm->is_deopt_mh_entry(_pc)) {
415         DEBUG_ONLY(verify_deopt_original_pc(sender_cm, _unextended_sp));
416       }
417     }
418   }
419 }
420 
421 //------------------------------------------------------------------------------
422 // frame::update_map_with_saved_link
423 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
424   // The interpreter and compiler(s) always save fp in a known
425   // location on entry. We must record where that location is
426   // so that if fp was live on callout from c2 we can find
427   // the saved copy no matter what it called.
428 
429   // Since the interpreter always saves fp if we record where it is then
430   // we don't have to always save fp on entry and exit to c2 compiled
431   // code, on entry will be enough.
432   map->set_location(rfp->as_VMReg(), (address) link_addr);
433   // this is weird "H" ought to be at a higher address however the
434   // oopMaps seems to have the "H" regs at the same address and the
435   // vanilla register.
436   // XXXX make this go away
437   if (true) {
438     map->set_location(rfp->as_VMReg()->next(), (address) link_addr);
439   }
440 }
441 
442 
443 //------------------------------------------------------------------------------
444 // frame::sender_for_interpreter_frame
445 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
446   // SP is the raw SP from the sender after adapter or interpreter
447   // extension.
448   intptr_t* sender_sp = this->sender_sp();
449 
450   // This is the sp before any possible extension (adapter/locals).
451   intptr_t* unextended_sp = interpreter_frame_sender_sp();
452 
453 #if COMPILER2_OR_JVMCI
454   if (map->update_map()) {
455     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
456   }
457 #endif // COMPILER2_OR_JVMCI
458 
459   // For ROP protection, Interpreter will have signed the sender_pc, but there is no requirement to authenticate it here.
460   address sender_pc = pauth_strip_verifiable(sender_pc_maybe_signed(), (address)link());
461 
462   return frame(sender_sp, unextended_sp, link(), sender_pc);
463 }
464 
465 //------------------------------------------------------------------------------
466 // frame::sender_for_compiled_frame
467 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
468   // When the sp of a compiled frame is correct, we can get the correct sender sp
469   // by unextended sp + frame size.
470   // For the following two scenarios, the sp of a compiled frame is correct:
471   //  a) This compiled frame is built from the anchor.
472   //  b) This compiled frame is built from a callee frame, and the callee frame can
473   //    calculate its sp correctly.
474   //
475   // For b), if the callee frame is a native code frame (such as leaf call), the sp of
476   // the compiled frame cannot be calculated correctly. There is currently no suitable
477   // solution to solve this problem perfectly. But when PreserveFramePointer is enabled,
478   // we can get the correct sender sp by fp + 2 (that is sender_sp()).
479 
480   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
481   intptr_t* l_sender_sp = (!PreserveFramePointer || _sp_is_trusted) ? unextended_sp() + _cb->frame_size()
482                                                                     : sender_sp();
483   intptr_t* unextended_sp = l_sender_sp;
484 
485   // the return_address is always the word on the stack
486 
487   // For ROP protection, C1/C2 will have signed the sender_pc, but there is no requirement to authenticate it here.
488   address sender_pc = pauth_strip_verifiable((address) *(l_sender_sp-1), (address) *(l_sender_sp-2));
489 
490   intptr_t** saved_fp_addr = (intptr_t**) (l_sender_sp - frame::sender_sp_offset);
491 
492   // assert (sender_sp() == l_sender_sp, "should be");
493   // assert (*saved_fp_addr == link(), "should be");
494 
495   if (map->update_map()) {
496     // Tell GC to use argument oopmaps for some runtime stubs that need it.
497     // For C1, the runtime stub might not have oop maps, so set this flag
498     // outside of update_register_map.
499     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
500     if (_cb->oop_maps() != NULL) {
501       OopMapSet::update_register_map(this, map);
502     }
503 
504     // Since the prolog does the save and restore of FP there is no
505     // oopmap for it so we must fill in its location as if there was
506     // an oopmap entry since if our caller was compiled code there
507     // could be live jvm state in it.
508     update_map_with_saved_link(map, saved_fp_addr);
509   }
510 
511   return frame(l_sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
512 }
513 
514 //------------------------------------------------------------------------------
515 // frame::sender_raw
516 frame frame::sender_raw(RegisterMap* map) const {
517   // Default is we done have to follow them. The sender_for_xxx will
518   // update it accordingly
519    map->set_include_argument_oops(false);
520 
521   if (is_entry_frame())
522     return sender_for_entry_frame(map);
523   if (is_interpreted_frame())
524     return sender_for_interpreter_frame(map);
525   assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
526 
527   // This test looks odd: why is it not is_compiled_frame() ?  That's
528   // because stubs also have OOP maps.
529   if (_cb != NULL) {
530     return sender_for_compiled_frame(map);
531   }
532 
533   // Must be native-compiled frame, i.e. the marshaling code for native
534   // methods that exists in the core system.
535 
536   // Native code may or may not have signed the return address, we have no way to be sure or what
537   // signing methods they used. Instead, just ensure the stripped value is used.
538 
539   return frame(sender_sp(), link(), sender_pc());
540 }
541 
542 frame frame::sender(RegisterMap* map) const {
543   frame result = sender_raw(map);
544 
545   if (map->process_frames()) {
546     StackWatermarkSet::on_iteration(map->thread(), result);
547   }
548 
549   return result;
550 }
551 
552 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
553   assert(is_interpreted_frame(), "Not an interpreted frame");
554   // These are reasonable sanity checks
555   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
556     return false;
557   }
558   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
559     return false;
560   }
561   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
562     return false;
563   }
564   // These are hacks to keep us out of trouble.
565   // The problem with these is that they mask other problems
566   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
567     return false;
568   }
569 
570   // do some validation of frame elements
571 
572   // first the method
573 
574   Method* m = *interpreter_frame_method_addr();
575 
576   // validate the method we'd find in this potential sender
577   if (!Method::is_valid_method(m)) return false;
578 
579   // stack frames shouldn't be much larger than max_stack elements
580   // this test requires the use of unextended_sp which is the sp as seen by
581   // the current frame, and not sp which is the "raw" pc which could point
582   // further because of local variables of the callee method inserted after
583   // method arguments
584   if (fp() - unextended_sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
585     return false;
586   }
587 
588   // validate bci/bcx
589 
590   address  bcp    = interpreter_frame_bcp();
591   if (m->validate_bci_from_bcp(bcp) < 0) {
592     return false;
593   }
594 
595   // validate constantPoolCache*
596   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
597   if (MetaspaceObj::is_valid(cp) == false) return false;
598 
599   // validate locals
600 
601   address locals =  (address) *interpreter_frame_locals_addr();
602   return thread->is_in_stack_range_incl(locals, (address)fp());
603 }
604 
605 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
606   assert(is_interpreted_frame(), "interpreted frame expected");
607   Method* method = interpreter_frame_method();
608   BasicType type = method->result_type();
609 
610   intptr_t* tos_addr;
611   if (method->is_native()) {
612     // TODO : ensure AARCH64 does the same as Intel here i.e. push v0 then r0
613     // Prior to calling into the runtime to report the method_exit the possible
614     // return value is pushed to the native stack. If the result is a jfloat/jdouble
615     // then ST0 is saved before EAX/EDX. See the note in generate_native_result
616     tos_addr = (intptr_t*)sp();
617     if (type == T_FLOAT || type == T_DOUBLE) {
618       // This is times two because we do a push(ltos) after pushing XMM0
619       // and that takes two interpreter stack slots.
620       tos_addr += 2 * Interpreter::stackElementWords;
621     }
622   } else {
623     tos_addr = (intptr_t*)interpreter_frame_tos_address();
624   }
625 
626   switch (type) {
627     case T_OBJECT  :
628     case T_ARRAY   : {
629       oop obj;
630       if (method->is_native()) {
631         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
632       } else {
633         oop* obj_p = (oop*)tos_addr;
634         obj = (obj_p == NULL) ? (oop)NULL : *obj_p;
635       }
636       assert(Universe::is_in_heap_or_null(obj), "sanity check");
637       *oop_result = obj;
638       break;
639     }
640     case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
641     case T_BYTE    : value_result->b = *(jbyte*)tos_addr; break;
642     case T_CHAR    : value_result->c = *(jchar*)tos_addr; break;
643     case T_SHORT   : value_result->s = *(jshort*)tos_addr; break;
644     case T_INT     : value_result->i = *(jint*)tos_addr; break;
645     case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
646     case T_FLOAT   : {
647         value_result->f = *(jfloat*)tos_addr;
648       break;
649     }
650     case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
651     case T_VOID    : /* Nothing to do */ break;
652     default        : ShouldNotReachHere();
653   }
654 
655   return type;
656 }
657 
658 
659 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
660   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
661   return &interpreter_frame_tos_address()[index];
662 }
663 
664 #ifndef PRODUCT
665 
666 #define DESCRIBE_FP_OFFSET(name) \
667   values.describe(frame_no, fp() + frame::name##_offset, #name)
668 
669 void frame::describe_pd(FrameValues& values, int frame_no) {
670   if (is_interpreted_frame()) {
671     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
672     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
673     DESCRIBE_FP_OFFSET(interpreter_frame_method);
674     DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
675     DESCRIBE_FP_OFFSET(interpreter_frame_mirror);
676     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
677     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
678     DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
679     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
680   }
681 }
682 #endif
683 
684 intptr_t *frame::initial_deoptimization_info() {
685   // Not used on aarch64, but we must return something.
686   return NULL;
687 }
688 
689 intptr_t* frame::real_fp() const {
690   if (_cb != NULL) {
691     // use the frame size if valid
692     int size = _cb->frame_size();
693     if (size > 0) {
694       return unextended_sp() + size;
695     }
696   }
697   // else rely on fp()
698   assert(! is_compiled_frame(), "unknown compiled frame size");
699   return fp();
700 }
701 
702 #undef DESCRIBE_FP_OFFSET
703 
704 #define DESCRIBE_FP_OFFSET(name)                     \
705   {                                                  \
706     uintptr_t *p = (uintptr_t *)fp;                  \
707     printf(INTPTR_FORMAT " " INTPTR_FORMAT " %s\n",  \
708            (uintptr_t)(p + frame::name##_offset),    \
709            p[frame::name##_offset], #name);          \
710   }
711 
712 static THREAD_LOCAL uintptr_t nextfp;
713 static THREAD_LOCAL uintptr_t nextpc;
714 static THREAD_LOCAL uintptr_t nextsp;
715 static THREAD_LOCAL RegisterMap *reg_map;
716 
717 static void printbc(Method *m, intptr_t bcx) {
718   const char *name;
719   char buf[16];
720   if (m->validate_bci_from_bcp((address)bcx) < 0
721       || !m->contains((address)bcx)) {
722     name = "???";
723     snprintf(buf, sizeof buf, "(bad)");
724   } else {
725     int bci = m->bci_from((address)bcx);
726     snprintf(buf, sizeof buf, "%d", bci);
727     name = Bytecodes::name(m->code_at(bci));
728   }
729   ResourceMark rm;
730   printf("%s : %s ==> %s\n", m->name_and_sig_as_C_string(), buf, name);
731 }
732 
733 void internal_pf(uintptr_t sp, uintptr_t fp, uintptr_t pc, uintptr_t bcx) {
734   if (! fp)
735     return;
736 
737   DESCRIBE_FP_OFFSET(return_addr);
738   DESCRIBE_FP_OFFSET(link);
739   DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
740   DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
741   DESCRIBE_FP_OFFSET(interpreter_frame_method);
742   DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
743   DESCRIBE_FP_OFFSET(interpreter_frame_cache);
744   DESCRIBE_FP_OFFSET(interpreter_frame_locals);
745   DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
746   DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
747   uintptr_t *p = (uintptr_t *)fp;
748 
749   // We want to see all frames, native and Java.  For compiled and
750   // interpreted frames we have special information that allows us to
751   // unwind them; for everything else we assume that the native frame
752   // pointer chain is intact.
753   frame this_frame((intptr_t*)sp, (intptr_t*)fp, (address)pc);
754   if (this_frame.is_compiled_frame() ||
755       this_frame.is_interpreted_frame()) {
756     frame sender = this_frame.sender(reg_map);
757     nextfp = (uintptr_t)sender.fp();
758     nextpc = (uintptr_t)sender.pc();
759     nextsp = (uintptr_t)sender.unextended_sp();
760   } else {
761     nextfp = p[frame::link_offset];
762     nextpc = p[frame::return_addr_offset];
763     nextsp = (uintptr_t)&p[frame::sender_sp_offset];
764   }
765 
766   if (bcx == -1ULL)
767     bcx = p[frame::interpreter_frame_bcp_offset];
768 
769   if (Interpreter::contains((address)pc)) {
770     Method* m = (Method*)p[frame::interpreter_frame_method_offset];
771     if(m && m->is_method()) {
772       printbc(m, bcx);
773     } else
774       printf("not a Method\n");
775   } else {
776     CodeBlob *cb = CodeCache::find_blob((address)pc);
777     if (cb != NULL) {
778       if (cb->is_nmethod()) {
779         ResourceMark rm;
780         nmethod* nm = (nmethod*)cb;
781         printf("nmethod %s\n", nm->method()->name_and_sig_as_C_string());
782       } else if (cb->name()) {
783         printf("CodeBlob %s\n", cb->name());
784       }
785     }
786   }
787 }
788 
789 extern "C" void npf() {
790   CodeBlob *cb = CodeCache::find_blob((address)nextpc);
791   // C2 does not always chain the frame pointers when it can, instead
792   // preferring to use fixed offsets from SP, so a simple leave() does
793   // not work.  Instead, it adds the frame size to SP then pops FP and
794   // LR.  We have to do the same thing to get a good call chain.
795   if (cb && cb->frame_size())
796     nextfp = nextsp + wordSize * (cb->frame_size() - 2);
797   internal_pf (nextsp, nextfp, nextpc, -1);
798 }
799 
800 extern "C" void pf(uintptr_t sp, uintptr_t fp, uintptr_t pc,
801                    uintptr_t bcx, uintptr_t thread) {
802   if (!reg_map) {
803     reg_map = NEW_C_HEAP_OBJ(RegisterMap, mtInternal);
804     ::new (reg_map) RegisterMap((JavaThread*)thread, false);
805   } else {
806     *reg_map = RegisterMap((JavaThread*)thread, false);
807   }
808 
809   {
810     CodeBlob *cb = CodeCache::find_blob((address)pc);
811     if (cb && cb->frame_size())
812       fp = sp + wordSize * (cb->frame_size() - 2);
813   }
814   internal_pf(sp, fp, pc, bcx);
815 }
816 
817 // support for printing out where we are in a Java method
818 // needs to be passed current fp and bcp register values
819 // prints method name, bc index and bytecode name
820 extern "C" void pm(uintptr_t fp, uintptr_t bcx) {
821   DESCRIBE_FP_OFFSET(interpreter_frame_method);
822   uintptr_t *p = (uintptr_t *)fp;
823   Method* m = (Method*)p[frame::interpreter_frame_method_offset];
824   printbc(m, bcx);
825 }
826 
827 #ifndef PRODUCT
828 // This is a generic constructor which is only used by pns() in debug.cpp.
829 frame::frame(void* sp, void* fp, void* pc) {
830   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
831 }
832 
833 #endif
834 
835 void JavaFrameAnchor::make_walkable() {
836   // last frame set?
837   if (last_Java_sp() == NULL) return;
838   // already walkable?
839   if (walkable()) return;
840   vmassert(last_Java_sp() != NULL, "not called from Java code?");
841   vmassert(last_Java_pc() == NULL, "already walkable");
842   _last_Java_pc = (address)_last_Java_sp[-1];
843   vmassert(walkable(), "something went wrong");
844 }
845