1 /*
  2  * Copyright (c) 1997, 2023, 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   if (is_heap_frame()) {
 60     return true;
 61   }
 62   address   sp = (address)_sp;
 63   address   fp = (address)_fp;
 64   address   unextended_sp = (address)_unextended_sp;
 65 
 66   // consider stack guards when trying to determine "safe" stack pointers
 67   // sp must be within the usable part of the stack (not in guards)
 68   if (!thread->is_in_usable_stack(sp)) {
 69     return false;
 70   }
 71 
 72   // When we are running interpreted code the machine stack pointer, SP, is
 73   // set low enough so that the Java expression stack can grow and shrink
 74   // without ever exceeding the machine stack bounds.  So, ESP >= SP.
 75 
 76   // When we call out of an interpreted method, SP is incremented so that
 77   // the space between SP and ESP is removed.  The SP saved in the callee's
 78   // frame is the SP *before* this increment.  So, when we walk a stack of
 79   // interpreter frames the sender's SP saved in a frame might be less than
 80   // the SP at the point of call.
 81 
 82   // So unextended sp must be within the stack but we need not to check
 83   // that unextended sp >= sp
 84   if (!thread->is_in_full_stack_checked(unextended_sp)) {
 85     return false;
 86   }
 87 
 88   // an fp must be within the stack and above (but not equal) sp
 89   // second evaluation on fp+ is added to handle situation where fp is -1
 90   bool fp_safe = thread->is_in_stack_range_excl(fp, sp) &&
 91                  thread->is_in_full_stack_checked(fp + (return_addr_offset * sizeof(void*)));
 92 
 93   // We know sp/unextended_sp are safe only fp is questionable here
 94 
 95   // If the current frame is known to the code cache then we can attempt to
 96   // to construct the sender and do some validation of it. This goes a long way
 97   // toward eliminating issues when we get in frame construction code
 98 
 99   if (_cb != nullptr ) {
100 
101     // First check if frame is complete and tester is reliable
102     // Unfortunately we can only check frame complete for runtime stubs and nmethod
103     // other generic buffer blobs are more problematic so we just assume they are
104     // ok. adapter blobs never have a frame complete and are never ok.
105 
106     if (!_cb->is_frame_complete_at(_pc)) {
107       if (_cb->is_nmethod() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
108         return false;
109       }
110     }
111 
112     // Could just be some random pointer within the codeBlob
113     if (!_cb->code_contains(_pc)) {
114       return false;
115     }
116 
117     // Entry frame checks
118     if (is_entry_frame()) {
119       // an entry frame must have a valid fp.
120       return fp_safe && is_entry_frame_valid(thread);
121     } else if (is_upcall_stub_frame()) {
122       return fp_safe;
123     }
124 
125     intptr_t* sender_sp = nullptr;
126     intptr_t* sender_unextended_sp = nullptr;
127     address   sender_pc = nullptr;
128     intptr_t* saved_fp =  nullptr;
129 
130     if (is_interpreted_frame()) {
131       // fp must be safe
132       if (!fp_safe) {
133         return false;
134       }
135 
136       // for interpreted frames, the value below is the sender "raw" sp,
137       // which can be different from the sender unextended sp (the sp seen
138       // by the sender) because of current frame local variables
139       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
140       sender_unextended_sp = (intptr_t*) this->fp()[interpreter_frame_sender_sp_offset];
141       saved_fp = (intptr_t*) this->fp()[link_offset];
142       sender_pc = pauth_strip_verifiable((address) this->fp()[return_addr_offset], (address)saved_fp);
143 
144     } else {
145       // must be some sort of compiled/runtime frame
146       // fp does not have to be safe (although it could be check for c1?)
147 
148       // check for a valid frame_size, otherwise we are unlikely to get a valid sender_pc
149       if (_cb->frame_size() <= 0) {
150         return false;
151       }
152 
153       sender_sp = _unextended_sp + _cb->frame_size();
154       // Is sender_sp safe?
155       if (!thread->is_in_full_stack_checked((address)sender_sp)) {
156         return false;
157       }
158       // Note: frame::sender_sp_offset is only valid for compiled frame
159       intptr_t **saved_fp_addr = (intptr_t**) (sender_sp - frame::sender_sp_offset);
160       saved_fp = *saved_fp_addr;
161       sender_pc = pauth_strip_verifiable((address) *(sender_sp-1), (address)saved_fp);
162 
163       // Repair the sender sp if this is a method with scalarized inline type args
164       sender_sp = repair_sender_sp(sender_sp, saved_fp_addr);
165       sender_unextended_sp = sender_sp;
166     }
167     if (Continuation::is_return_barrier_entry(sender_pc)) {
168       // If our sender_pc is the return barrier, then our "real" sender is the continuation entry
169       frame s = Continuation::continuation_bottom_sender(thread, *this, sender_sp);
170       sender_sp = s.sp();
171       sender_pc = s.pc();
172     }
173 
174     // If the potential sender is the interpreter then we can do some more checking
175     if (Interpreter::contains(sender_pc)) {
176 
177       // fp is always saved in a recognizable place in any code we generate. However
178       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved fp
179       // is really a frame pointer.
180 
181       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
182         return false;
183       }
184 
185       // construct the potential sender
186 
187       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
188 
189       return sender.is_interpreted_frame_valid(thread);
190 
191     }
192 
193     // We must always be able to find a recognizable pc
194     CodeBlob* sender_blob = CodeCache::find_blob(sender_pc);
195     if (sender_pc == nullptr ||  sender_blob == nullptr) {
196       return false;
197     }
198 
199     // Could just be some random pointer within the codeBlob
200     if (!sender_blob->code_contains(sender_pc)) {
201       return false;
202     }
203 
204     // We should never be able to see an adapter if the current frame is something from code cache
205     if (sender_blob->is_adapter_blob()) {
206       return false;
207     }
208 
209     // Could be the call_stub
210     if (StubRoutines::returns_to_call_stub(sender_pc)) {
211       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
212         return false;
213       }
214 
215       // construct the potential sender
216 
217       frame sender(sender_sp, sender_unextended_sp, saved_fp, sender_pc);
218 
219       // Validate the JavaCallWrapper an entry frame must have
220       address jcw = (address)sender.entry_frame_call_wrapper();
221 
222       return thread->is_in_stack_range_excl(jcw, (address)sender.fp());
223     } else if (sender_blob->is_upcall_stub()) {
224       return false;
225     }
226 
227     CompiledMethod* nm = sender_blob->as_compiled_method_or_null();
228     if (nm != nullptr) {
229       if (nm->is_deopt_mh_entry(sender_pc) || nm->is_deopt_entry(sender_pc) ||
230           nm->method()->is_method_handle_intrinsic()) {
231         return false;
232       }
233     }
234 
235     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
236     // because the return address counts against the callee's frame.
237 
238     if (sender_blob->frame_size() <= 0) {
239       assert(!sender_blob->is_compiled(), "should count return address at least");
240       return false;
241     }
242 
243     // We should never be able to see anything here except an nmethod. If something in the
244     // code cache (current frame) is called by an entity within the code cache that entity
245     // should not be anything but the call stub (already covered), the interpreter (already covered)
246     // or an nmethod.
247 
248     if (!sender_blob->is_compiled()) {
249         return false;
250     }
251 
252     // Could put some more validation for the potential non-interpreted sender
253     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
254 
255     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
256 
257     // We've validated the potential sender that would be created
258     return true;
259   }
260 
261   // Must be native-compiled frame. Since sender will try and use fp to find
262   // linkages it must be safe
263 
264   if (!fp_safe) {
265     return false;
266   }
267 
268   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
269 
270   if ( (address) this->fp()[return_addr_offset] == nullptr) return false;
271 
272 
273   // could try and do some more potential verification of native frame if we could think of some...
274 
275   return true;
276 
277 }
278 
279 void frame::patch_pc(Thread* thread, address pc) {
280   assert(_cb == CodeCache::find_blob(pc), "unexpected pc");
281   address* pc_addr = &(((address*) sp())[-1]);
282   address signing_sp = (((address*) sp())[-2]);
283   address signed_pc = pauth_sign_return_address(pc, (address)signing_sp);
284   address pc_old = pauth_strip_verifiable(*pc_addr, (address)signing_sp);
285 
286   if (TracePcPatching) {
287     tty->print("patch_pc at address " INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "]",
288                   p2i(pc_addr), p2i(pc_old), p2i(pc));
289     if (VM_Version::use_rop_protection()) {
290       tty->print(" [signed " INTPTR_FORMAT " -> " INTPTR_FORMAT "]", p2i(*pc_addr), p2i(signed_pc));
291     }
292     tty->print_cr("");
293   }
294 
295   assert(!Continuation::is_return_barrier_entry(pc_old), "return barrier");
296 
297   // Either the return address is the original one or we are going to
298   // patch in the same address that's already there.
299   assert(_pc == pc_old || pc == pc_old || pc_old == 0, "");
300   DEBUG_ONLY(address old_pc = _pc;)
301   *pc_addr = signed_pc;
302   _pc = pc; // must be set before call to get_deopt_original_pc
303   address original_pc = CompiledMethod::get_deopt_original_pc(this);
304   if (original_pc != nullptr) {
305     assert(original_pc == old_pc, "expected original PC to be stored before patching");
306     _deopt_state = is_deoptimized;
307     _pc = original_pc;
308   } else {
309     _deopt_state = not_deoptimized;
310   }
311 }
312 
313 intptr_t* frame::entry_frame_argument_at(int offset) const {
314   // convert offset to index to deal with tsi
315   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
316   // Entry frame's arguments are always in relation to unextended_sp()
317   return &unextended_sp()[index];
318 }
319 
320 // locals
321 
322 void frame::interpreter_frame_set_locals(intptr_t* locs)  {
323   assert(is_interpreted_frame(), "interpreted frame expected");
324   // set relativized locals
325   ptr_at_put(interpreter_frame_locals_offset, (intptr_t) (locs - fp()));
326 }
327 
328 // sender_sp
329 
330 intptr_t* frame::interpreter_frame_sender_sp() const {
331   assert(is_interpreted_frame(), "interpreted frame expected");
332   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
333 }
334 
335 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
336   assert(is_interpreted_frame(), "interpreted frame expected");
337   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
338 }
339 
340 
341 // monitor elements
342 
343 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
344   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
345 }
346 
347 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
348   BasicObjectLock* result = (BasicObjectLock*) at(interpreter_frame_monitor_block_top_offset);
349   // make sure the pointer points inside the frame
350   assert(sp() <= (intptr_t*) result, "monitor end should be above the stack pointer");
351   assert((intptr_t*) result < fp(),  "monitor end should be strictly below the frame pointer");
352   return result;
353 }
354 
355 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
356   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
357 }
358 
359 // Used by template based interpreter deoptimization
360 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
361     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
362 }
363 
364 // Used by template based interpreter deoptimization
365 void frame::interpreter_frame_set_extended_sp(intptr_t* sp) {
366   *((intptr_t**)addr_at(interpreter_frame_extended_sp_offset)) = sp;
367 }
368 
369 frame frame::sender_for_entry_frame(RegisterMap* map) const {
370   assert(map != nullptr, "map must be set");
371   // Java frame called from C; skip all C frames and return top C
372   // frame of that chunk as the sender
373   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
374   assert(!entry_frame_is_first(), "next Java fp must be non zero");
375   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
376   // Since we are walking the stack now this nested anchor is obviously walkable
377   // even if it wasn't when it was stacked.
378   jfa->make_walkable();
379   map->clear();
380   assert(map->include_argument_oops(), "should be set by clear");
381   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
382   fr.set_sp_is_trusted();
383 
384   return fr;
385 }
386 
387 UpcallStub::FrameData* UpcallStub::frame_data_for_frame(const frame& frame) const {
388   assert(frame.is_upcall_stub_frame(), "wrong frame");
389   // need unextended_sp here, since normal sp is wrong for interpreter callees
390   return reinterpret_cast<UpcallStub::FrameData*>(
391     reinterpret_cast<address>(frame.unextended_sp()) + in_bytes(_frame_data_offset));
392 }
393 
394 bool frame::upcall_stub_frame_is_first() const {
395   assert(is_upcall_stub_frame(), "must be optimzed entry frame");
396   UpcallStub* blob = _cb->as_upcall_stub();
397   JavaFrameAnchor* jfa = blob->jfa_for_frame(*this);
398   return jfa->last_Java_sp() == nullptr;
399 }
400 
401 frame frame::sender_for_upcall_stub_frame(RegisterMap* map) const {
402   assert(map != nullptr, "map must be set");
403   UpcallStub* blob = _cb->as_upcall_stub();
404   // Java frame called from C; skip all C frames and return top C
405   // frame of that chunk as the sender
406   JavaFrameAnchor* jfa = blob->jfa_for_frame(*this);
407   assert(!upcall_stub_frame_is_first(), "must have a frame anchor to go back to");
408   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
409   // Since we are walking the stack now this nested anchor is obviously walkable
410   // even if it wasn't when it was stacked.
411   jfa->make_walkable();
412   map->clear();
413   assert(map->include_argument_oops(), "should be set by clear");
414   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
415 
416   return fr;
417 }
418 
419 //------------------------------------------------------------------------------
420 // frame::verify_deopt_original_pc
421 //
422 // Verifies the calculated original PC of a deoptimization PC for the
423 // given unextended SP.
424 #ifdef ASSERT
425 void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp) {
426   frame fr;
427 
428   // This is ugly but it's better than to change {get,set}_original_pc
429   // to take an SP value as argument.  And it's only a debugging
430   // method anyway.
431   fr._unextended_sp = unextended_sp;
432 
433   address original_pc = nm->get_original_pc(&fr);
434   assert(nm->insts_contains_inclusive(original_pc),
435          "original PC must be in the main code section of the compiled method (or must be immediately following it)");
436 }
437 #endif
438 
439 //------------------------------------------------------------------------------
440 // frame::adjust_unextended_sp
441 #ifdef ASSERT
442 void frame::adjust_unextended_sp() {
443   // On aarch64, sites calling method handle intrinsics and lambda forms are treated
444   // as any other call site. Therefore, no special action is needed when we are
445   // returning to any of these call sites.
446 
447   if (_cb != nullptr) {
448     CompiledMethod* sender_cm = _cb->as_compiled_method_or_null();
449     if (sender_cm != nullptr) {
450       // If the sender PC is a deoptimization point, get the original PC.
451       if (sender_cm->is_deopt_entry(_pc) ||
452           sender_cm->is_deopt_mh_entry(_pc)) {
453         verify_deopt_original_pc(sender_cm, _unextended_sp);
454       }
455     }
456   }
457 }
458 #endif
459 
460 
461 //------------------------------------------------------------------------------
462 // frame::sender_for_interpreter_frame
463 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
464   // SP is the raw SP from the sender after adapter or interpreter
465   // extension.
466   intptr_t* sender_sp = this->sender_sp();
467 
468   // This is the sp before any possible extension (adapter/locals).
469   intptr_t* unextended_sp = interpreter_frame_sender_sp();
470   intptr_t* sender_fp = link();
471 
472 #if COMPILER2_OR_JVMCI
473   if (map->update_map()) {
474     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
475   }
476 #endif // COMPILER2_OR_JVMCI
477 
478   // For ROP protection, Interpreter will have signed the sender_pc, but there is no requirement to authenticate it here.
479   address sender_pc = pauth_strip_verifiable(sender_pc_maybe_signed(), (address)link());
480 
481   if (Continuation::is_return_barrier_entry(sender_pc)) {
482     if (map->walk_cont()) { // about to walk into an h-stack
483       return Continuation::top_frame(*this, map);
484     } else {
485       return Continuation::continuation_bottom_sender(map->thread(), *this, sender_sp);
486     }
487   }
488 
489   return frame(sender_sp, unextended_sp, sender_fp, sender_pc);
490 }
491 
492 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
493   assert(is_interpreted_frame(), "Not an interpreted frame");
494   // These are reasonable sanity checks
495   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
496     return false;
497   }
498   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
499     return false;
500   }
501   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
502     return false;
503   }
504   // These are hacks to keep us out of trouble.
505   // The problem with these is that they mask other problems
506   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
507     return false;
508   }
509 
510   // do some validation of frame elements
511 
512   // first the method
513 
514   Method* m = *interpreter_frame_method_addr();
515 
516   // validate the method we'd find in this potential sender
517   if (!Method::is_valid_method(m)) return false;
518 
519   // stack frames shouldn't be much larger than max_stack elements
520   // this test requires the use of unextended_sp which is the sp as seen by
521   // the current frame, and not sp which is the "raw" pc which could point
522   // further because of local variables of the callee method inserted after
523   // method arguments
524   if (fp() - unextended_sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
525     return false;
526   }
527 
528   // validate bci/bcx
529 
530   address  bcp    = interpreter_frame_bcp();
531   if (m->validate_bci_from_bcp(bcp) < 0) {
532     return false;
533   }
534 
535   // validate constantPoolCache*
536   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
537   if (MetaspaceObj::is_valid(cp) == false) return false;
538 
539   // validate locals
540 
541   address locals =  (address)interpreter_frame_locals();
542   return thread->is_in_stack_range_incl(locals, (address)fp());
543 }
544 
545 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
546   assert(is_interpreted_frame(), "interpreted frame expected");
547   Method* method = interpreter_frame_method();
548   BasicType type = method->result_type();
549 
550   intptr_t* tos_addr;
551   if (method->is_native()) {
552     // TODO : ensure AARCH64 does the same as Intel here i.e. push v0 then r0
553     // Prior to calling into the runtime to report the method_exit the possible
554     // return value is pushed to the native stack. If the result is a jfloat/jdouble
555     // then ST0 is saved before EAX/EDX. See the note in generate_native_result
556     tos_addr = (intptr_t*)sp();
557     if (type == T_FLOAT || type == T_DOUBLE) {
558       // This is times two because we do a push(ltos) after pushing XMM0
559       // and that takes two interpreter stack slots.
560       tos_addr += 2 * Interpreter::stackElementWords;
561     }
562   } else {
563     tos_addr = (intptr_t*)interpreter_frame_tos_address();
564   }
565 
566   switch (type) {
567     case T_PRIMITIVE_OBJECT :
568     case T_OBJECT  :
569     case T_ARRAY   : {
570       oop obj;
571       if (method->is_native()) {
572         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
573       } else {
574         oop* obj_p = (oop*)tos_addr;
575         obj = (obj_p == nullptr) ? (oop)nullptr : *obj_p;
576       }
577       assert(Universe::is_in_heap_or_null(obj), "sanity check");
578       *oop_result = obj;
579       break;
580     }
581     case T_BOOLEAN : value_result->z = *(jboolean*)tos_addr; break;
582     case T_BYTE    : value_result->b = *(jbyte*)tos_addr; break;
583     case T_CHAR    : value_result->c = *(jchar*)tos_addr; break;
584     case T_SHORT   : value_result->s = *(jshort*)tos_addr; break;
585     case T_INT     : value_result->i = *(jint*)tos_addr; break;
586     case T_LONG    : value_result->j = *(jlong*)tos_addr; break;
587     case T_FLOAT   : {
588         value_result->f = *(jfloat*)tos_addr;
589       break;
590     }
591     case T_DOUBLE  : value_result->d = *(jdouble*)tos_addr; break;
592     case T_VOID    : /* Nothing to do */ break;
593     default        : ShouldNotReachHere();
594   }
595 
596   return type;
597 }
598 
599 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
600   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
601   return &interpreter_frame_tos_address()[index];
602 }
603 
604 #ifndef PRODUCT
605 
606 #define DESCRIBE_FP_OFFSET(name) \
607   values.describe(frame_no, fp() + frame::name##_offset, #name)
608 
609 void frame::describe_pd(FrameValues& values, int frame_no) {
610   if (is_interpreted_frame()) {
611     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
612     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
613     DESCRIBE_FP_OFFSET(interpreter_frame_method);
614     DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
615     DESCRIBE_FP_OFFSET(interpreter_frame_extended_sp);
616     DESCRIBE_FP_OFFSET(interpreter_frame_mirror);
617     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
618     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
619     DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
620     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
621   }
622 
623   if (is_java_frame() || Continuation::is_continuation_enterSpecial(*this)) {
624     intptr_t* ret_pc_loc;
625     intptr_t* fp_loc;
626     if (is_interpreted_frame()) {
627       ret_pc_loc = fp() + return_addr_offset;
628       fp_loc = fp();
629     } else {
630       ret_pc_loc = real_fp() - return_addr_offset;
631       fp_loc = real_fp() - sender_sp_offset;
632     }
633     address ret_pc = *(address*)ret_pc_loc;
634     values.describe(frame_no, ret_pc_loc,
635       Continuation::is_return_barrier_entry(ret_pc) ? "return address (return barrier)" : "return address");
636     values.describe(-1, fp_loc, "saved fp", 0); // "unowned" as value belongs to sender
637   }
638 }
639 #endif
640 
641 intptr_t *frame::initial_deoptimization_info() {
642   // Not used on aarch64, but we must return something.
643   return nullptr;
644 }
645 
646 #undef DESCRIBE_FP_OFFSET
647 
648 #define DESCRIBE_FP_OFFSET(name)                     \
649   {                                                  \
650     uintptr_t *p = (uintptr_t *)fp;                  \
651     printf(INTPTR_FORMAT " " INTPTR_FORMAT " %s\n",  \
652            (uintptr_t)(p + frame::name##_offset),    \
653            p[frame::name##_offset], #name);          \
654   }
655 
656 static THREAD_LOCAL uintptr_t nextfp;
657 static THREAD_LOCAL uintptr_t nextpc;
658 static THREAD_LOCAL uintptr_t nextsp;
659 static THREAD_LOCAL RegisterMap *reg_map;
660 
661 static void printbc(Method *m, intptr_t bcx) {
662   const char *name;
663   char buf[16];
664   if (m->validate_bci_from_bcp((address)bcx) < 0
665       || !m->contains((address)bcx)) {
666     name = "???";
667     snprintf(buf, sizeof buf, "(bad)");
668   } else {
669     int bci = m->bci_from((address)bcx);
670     snprintf(buf, sizeof buf, "%d", bci);
671     name = Bytecodes::name(m->code_at(bci));
672   }
673   ResourceMark rm;
674   printf("%s : %s ==> %s\n", m->name_and_sig_as_C_string(), buf, name);
675 }
676 
677 void internal_pf(uintptr_t sp, uintptr_t fp, uintptr_t pc, uintptr_t bcx) {
678   if (! fp)
679     return;
680 
681   DESCRIBE_FP_OFFSET(return_addr);
682   DESCRIBE_FP_OFFSET(link);
683   DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
684   DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
685   DESCRIBE_FP_OFFSET(interpreter_frame_method);
686   DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
687   DESCRIBE_FP_OFFSET(interpreter_frame_extended_sp);
688   DESCRIBE_FP_OFFSET(interpreter_frame_mirror);
689   DESCRIBE_FP_OFFSET(interpreter_frame_cache);
690   DESCRIBE_FP_OFFSET(interpreter_frame_locals);
691   DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
692   DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
693   uintptr_t *p = (uintptr_t *)fp;
694 
695   // We want to see all frames, native and Java.  For compiled and
696   // interpreted frames we have special information that allows us to
697   // unwind them; for everything else we assume that the native frame
698   // pointer chain is intact.
699   frame this_frame((intptr_t*)sp, (intptr_t*)fp, (address)pc);
700   if (this_frame.is_compiled_frame() ||
701       this_frame.is_interpreted_frame()) {
702     frame sender = this_frame.sender(reg_map);
703     nextfp = (uintptr_t)sender.fp();
704     nextpc = (uintptr_t)sender.pc();
705     nextsp = (uintptr_t)sender.unextended_sp();
706   } else {
707     nextfp = p[frame::link_offset];
708     nextpc = p[frame::return_addr_offset];
709     nextsp = (uintptr_t)&p[frame::sender_sp_offset];
710   }
711 
712   if (bcx == -1ULL)
713     bcx = p[frame::interpreter_frame_bcp_offset];
714 
715   if (Interpreter::contains((address)pc)) {
716     Method* m = (Method*)p[frame::interpreter_frame_method_offset];
717     if(m && m->is_method()) {
718       printbc(m, bcx);
719     } else
720       printf("not a Method\n");
721   } else {
722     CodeBlob *cb = CodeCache::find_blob((address)pc);
723     if (cb != nullptr) {
724       if (cb->is_nmethod()) {
725         ResourceMark rm;
726         nmethod* nm = (nmethod*)cb;
727         printf("nmethod %s\n", nm->method()->name_and_sig_as_C_string());
728       } else if (cb->name()) {
729         printf("CodeBlob %s\n", cb->name());
730       }
731     }
732   }
733 }
734 
735 extern "C" void npf() {
736   CodeBlob *cb = CodeCache::find_blob((address)nextpc);
737   // C2 does not always chain the frame pointers when it can, instead
738   // preferring to use fixed offsets from SP, so a simple leave() does
739   // not work.  Instead, it adds the frame size to SP then pops FP and
740   // LR.  We have to do the same thing to get a good call chain.
741   if (cb && cb->frame_size())
742     nextfp = nextsp + wordSize * (cb->frame_size() - 2);
743   internal_pf (nextsp, nextfp, nextpc, -1);
744 }
745 
746 extern "C" void pf(uintptr_t sp, uintptr_t fp, uintptr_t pc,
747                    uintptr_t bcx, uintptr_t thread) {
748   if (!reg_map) {
749     reg_map = NEW_C_HEAP_OBJ(RegisterMap, mtInternal);
750     ::new (reg_map) RegisterMap(reinterpret_cast<JavaThread*>(thread),
751                                 RegisterMap::UpdateMap::skip,
752                                 RegisterMap::ProcessFrames::include,
753                                 RegisterMap::WalkContinuation::skip);
754   } else {
755     *reg_map = RegisterMap(reinterpret_cast<JavaThread*>(thread),
756                            RegisterMap::UpdateMap::skip,
757                            RegisterMap::ProcessFrames::include,
758                            RegisterMap::WalkContinuation::skip);
759   }
760 
761   {
762     CodeBlob *cb = CodeCache::find_blob((address)pc);
763     if (cb && cb->frame_size())
764       fp = sp + wordSize * (cb->frame_size() - 2);
765   }
766   internal_pf(sp, fp, pc, bcx);
767 }
768 
769 // support for printing out where we are in a Java method
770 // needs to be passed current fp and bcp register values
771 // prints method name, bc index and bytecode name
772 extern "C" void pm(uintptr_t fp, uintptr_t bcx) {
773   DESCRIBE_FP_OFFSET(interpreter_frame_method);
774   uintptr_t *p = (uintptr_t *)fp;
775   Method* m = (Method*)p[frame::interpreter_frame_method_offset];
776   printbc(m, bcx);
777 }
778 
779 #ifndef PRODUCT
780 // This is a generic constructor which is only used by pns() in debug.cpp.
781 frame::frame(void* sp, void* fp, void* pc) {
782   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
783 }
784 
785 #endif
786 
787 // Check for a method with scalarized inline type arguments that needs
788 // a stack repair and return the repaired sender stack pointer.
789 intptr_t* frame::repair_sender_sp(intptr_t* sender_sp, intptr_t** saved_fp_addr) const {
790   CompiledMethod* cm = _cb->as_compiled_method_or_null();
791   if (cm != nullptr && cm->needs_stack_repair()) {
792     // The stack increment resides just below the saved FP on the stack and
793     // records the total frame size excluding the two words for saving FP and LR.
794     intptr_t* sp_inc_addr = (intptr_t*) (saved_fp_addr - 1);
795     assert(*sp_inc_addr % StackAlignmentInBytes == 0, "sp_inc not aligned");
796     int real_frame_size = (*sp_inc_addr / wordSize) + 2;
797     assert(real_frame_size >= _cb->frame_size() && real_frame_size <= 1000000, "invalid frame size");
798     sender_sp = unextended_sp() + real_frame_size;
799   }
800   return sender_sp;
801 }
802 
803 void JavaFrameAnchor::make_walkable() {
804   // last frame set?
805   if (last_Java_sp() == nullptr) return;
806   // already walkable?
807   if (walkable()) return;
808   vmassert(last_Java_sp() != nullptr, "not called from Java code?");
809   vmassert(last_Java_pc() == nullptr, "already walkable");
810   _last_Java_pc = (address)_last_Java_sp[-1];
811   vmassert(walkable(), "something went wrong");
812 }