1 /*
  2  * Copyright (c) 2008, 2021, 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 "compiler/oopMap.hpp"
 27 #include "interpreter/interpreter.hpp"
 28 #include "memory/resourceArea.hpp"
 29 #include "memory/universe.hpp"
 30 #include "oops/markWord.hpp"
 31 #include "oops/method.hpp"
 32 #include "oops/oop.inline.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/os.inline.hpp"
 38 #include "runtime/signature.hpp"
 39 #include "runtime/stubCodeGenerator.hpp"
 40 #include "runtime/stubRoutines.hpp"
 41 #include "vmreg_arm.inline.hpp"
 42 #ifdef COMPILER1
 43 #include "c1/c1_Runtime1.hpp"
 44 #include "runtime/vframeArray.hpp"
 45 #endif
 46 #include "prims/methodHandles.hpp"
 47 
 48 #ifdef ASSERT
 49 void RegisterMap::check_location_valid() {
 50 }
 51 #endif
 52 
 53 
 54 // Profiling/safepoint support
 55 
 56 bool frame::safe_for_sender(JavaThread *thread) {
 57   address   sp = (address)_sp;
 58   address   fp = (address)_fp;
 59   address   unextended_sp = (address)_unextended_sp;
 60 
 61   // consider stack guards when trying to determine "safe" stack pointers
 62   // sp must be within the usable part of the stack (not in guards)
 63   if (!thread->is_in_usable_stack(sp)) {
 64     return false;
 65   }
 66 
 67   if (!thread->is_in_stack_range_incl(unextended_sp, sp)) {
 68     return false;
 69   }
 70 
 71   // We know sp/unextended_sp are safe. Only fp is questionable here.
 72 
 73   bool fp_safe = thread->is_in_stack_range_incl(fp, sp);
 74 
 75   if (_cb != NULL ) {
 76 
 77     // First check if frame is complete and tester is reliable
 78     // Unfortunately we can only check frame complete for runtime stubs and nmethod
 79     // other generic buffer blobs are more problematic so we just assume they are
 80     // ok. adapter blobs never have a frame complete and are never ok.
 81 
 82     if (!_cb->is_frame_complete_at(_pc)) {
 83       if (_cb->is_compiled() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
 84         return false;
 85       }
 86     }
 87 
 88     // Could just be some random pointer within the codeBlob
 89     if (!_cb->code_contains(_pc)) {
 90       return false;
 91     }
 92 
 93     // Entry frame checks
 94     if (is_entry_frame()) {
 95       // an entry frame must have a valid fp.
 96       return fp_safe && is_entry_frame_valid(thread);
 97     }
 98 
 99     intptr_t* sender_sp = NULL;
100     address   sender_pc = NULL;
101 
102     if (is_interpreted_frame()) {
103       // fp must be safe
104       if (!fp_safe) {
105         return false;
106       }
107 
108       sender_pc = (address) this->fp()[return_addr_offset];
109       sender_sp = (intptr_t*) addr_at(sender_sp_offset);
110 
111     } else {
112       // must be some sort of compiled/runtime frame
113       // fp does not have to be safe (although it could be check for c1?)
114 
115       sender_sp = _unextended_sp + _cb->frame_size();
116       // Is sender_sp safe?
117       if (!thread->is_in_full_stack_checked((address)sender_sp)) {
118         return false;
119       }
120       // With our calling conventions, the return_address should
121       // end up being the word on the stack
122       sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
123     }
124 
125     // We must always be able to find a recognizable pc
126     CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
127     if (sender_pc == NULL || sender_blob == NULL) {
128       return false;
129     }
130 
131 
132     // If the potential sender is the interpreter then we can do some more checking
133     if (Interpreter::contains(sender_pc)) {
134 
135       // FP is always saved in a recognizable place in any code we generate. However
136       // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved FP
137       // is really a frame pointer.
138 
139       intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
140       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
141         return false;
142       }
143 
144       // construct the potential sender
145 
146       frame sender(sender_sp, saved_fp, sender_pc);
147 
148       return sender.is_interpreted_frame_valid(thread);
149     }
150 
151     if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
152       return false;
153     }
154 
155     // Could just be some random pointer within the codeBlob
156     if (!sender_blob->code_contains(sender_pc)) {
157       return false;
158     }
159 
160     // We should never be able to see an adapter if the current frame is something from code cache
161     if (sender_blob->is_adapter_blob()) {
162       return false;
163     }
164 
165     // Could be the call_stub
166     if (StubRoutines::returns_to_call_stub(sender_pc)) {
167       intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
168       if (!thread->is_in_stack_range_excl((address)saved_fp, (address)sender_sp)) {
169         return false;
170       }
171 
172       // construct the potential sender
173 
174       frame sender(sender_sp, saved_fp, sender_pc);
175 
176       // Validate the JavaCallWrapper an entry frame must have
177       address jcw = (address)sender.entry_frame_call_wrapper();
178 
179       return thread->is_in_stack_range_excl(jcw, (address)sender.fp());
180     }
181 
182     // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
183     // because the return address counts against the callee's frame.
184 
185     if (sender_blob->frame_size() <= 0) {
186       assert(!sender_blob->is_compiled(), "should count return address at least");
187       return false;
188     }
189 
190     // We should never be able to see anything here except an nmethod. If something in the
191     // code cache (current frame) is called by an entity within the code cache that entity
192     // should not be anything but the call stub (already covered), the interpreter (already covered)
193     // or an nmethod.
194 
195     if (!sender_blob->is_compiled()) {
196       return false;
197     }
198 
199     // Could put some more validation for the potential non-interpreted sender
200     // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
201 
202     // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
203 
204     // We've validated the potential sender that would be created
205     return true;
206   }
207 
208   // Must be native-compiled frame. Since sender will try and use fp to find
209   // linkages it must be safe
210 
211   if (!fp_safe) {
212     return false;
213   }
214 
215   // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
216 
217   if ((address) this->fp()[return_addr_offset] == NULL) return false;
218 
219 
220   // could try and do some more potential verification of native frame if we could think of some...
221 
222   return true;
223 }
224 
225 
226 void frame::patch_pc(Thread* thread, address pc) {
227   assert(_cb == CodeCache::find_blob(pc), "unexpected pc");
228   address* pc_addr = &((address *)sp())[-sender_sp_offset+return_addr_offset];
229   if (TracePcPatching) {
230     tty->print_cr("patch_pc at address" INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "] ",
231                   p2i(pc_addr), p2i(*pc_addr), p2i(pc));
232   }
233   DEBUG_ONLY(address old_pc = _pc;)
234   *pc_addr = pc;
235   _pc = pc; // must be set before call to get_deopt_original_pc
236   address original_pc = CompiledMethod::get_deopt_original_pc(this);
237   if (original_pc != NULL) {
238     assert(original_pc == old_pc, "expected original PC to be stored before patching");
239     _deopt_state = is_deoptimized;
240     // leave _pc as is
241   } else {
242     _deopt_state = not_deoptimized;
243     _pc = pc;
244   }
245 }
246 
247 bool frame::is_interpreted_frame() const  {
248   return Interpreter::contains(pc());
249 }
250 





251 intptr_t* frame::entry_frame_argument_at(int offset) const {
252   assert(is_entry_frame(), "entry frame expected");
253   // convert offset to index to deal with tsi
254   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
255   // Entry frame's arguments are always in relation to unextended_sp()
256   return &unextended_sp()[index];
257 }
258 
259 // sender_sp
260 intptr_t* frame::interpreter_frame_sender_sp() const {
261   assert(is_interpreted_frame(), "interpreted frame expected");
262   return (intptr_t*) at(interpreter_frame_sender_sp_offset);
263 }
264 
265 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
266   assert(is_interpreted_frame(), "interpreted frame expected");
267   ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
268 }
269 
270 
271 // monitor elements
272 
273 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
274   return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
275 }
276 
277 // Pointer beyond the "oldest/deepest" BasicObjectLock on stack.
278 template BasicObjectLock* frame::interpreter_frame_monitor_end<true>() const;
279 template BasicObjectLock* frame::interpreter_frame_monitor_end<false>() const;
280 
281 template <bool relative>
282 inline BasicObjectLock* frame::interpreter_frame_monitor_end() const {
283   BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
284   // make sure the pointer points inside the frame
285   assert((intptr_t) fp() >  (intptr_t) result, "result must <  than frame pointer");
286   assert((intptr_t) sp() <= (intptr_t) result, "result must >= than stack pointer");
287   return result;
288 }
289 
290 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
291   *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
292 }
293 
294 
295 // Used by template based interpreter deoptimization
296 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
297     *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
298 }
299 
300 
301 frame frame::sender_for_entry_frame(RegisterMap* map) const {
302   assert(map != NULL, "map must be set");
303   // Java frame called from C; skip all C frames and return top C
304   // frame of that chunk as the sender
305   JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
306   assert(!entry_frame_is_first(), "next Java fp must be non zero");
307   assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
308   map->clear();
309   assert(map->include_argument_oops(), "should be set by clear");
310   if (jfa->last_Java_pc() != NULL) {
311     frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
312     return fr;
313   }
314   frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
315   return fr;
316 }
317 
318 OptimizedEntryBlob::FrameData* OptimizedEntryBlob::frame_data_for_frame(const frame& frame) const {
319   ShouldNotCallThis();
320   return nullptr;
321 }
322 
323 bool frame::optimized_entry_frame_is_first() const {
324   ShouldNotCallThis();
325   return false;
326 }
327 
328 //------------------------------------------------------------------------------
329 // frame::verify_deopt_original_pc
330 //
331 // Verifies the calculated original PC of a deoptimization PC for the
332 // given unextended SP.  The unextended SP might also be the saved SP
333 // for MethodHandle call sites.
334 #ifdef ASSERT
335 void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
336   frame fr;
337 
338   // This is ugly but it's better than to change {get,set}_original_pc
339   // to take an SP value as argument.  And it's only a debugging
340   // method anyway.
341   fr._unextended_sp = unextended_sp;
342 
343   address original_pc = nm->get_original_pc(&fr);
344   assert(nm->insts_contains_inclusive(original_pc),
345          "original PC must be in the main code section of the the compiled method (or must be immediately following it)");
346   assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
347 }
348 #endif
349 
350 //------------------------------------------------------------------------------
351 // frame::adjust_unextended_sp
352 void frame::adjust_unextended_sp() {
353   // same as on x86
354 
355   // If we are returning to a compiled MethodHandle call site, the
356   // saved_fp will in fact be a saved value of the unextended SP.  The
357   // simplest way to tell whether we are returning to such a call site
358   // is as follows:
359 
360   CompiledMethod* sender_cm = (_cb == NULL) ? NULL : _cb->as_compiled_method_or_null();
361   if (sender_cm != NULL) {
362     // If the sender PC is a deoptimization point, get the original
363     // PC.  For MethodHandle call site the unextended_sp is stored in
364     // saved_fp.
365     if (sender_cm->is_deopt_mh_entry(_pc)) {
366       DEBUG_ONLY(verify_deopt_mh_original_pc(sender_cm, _fp));
367       _unextended_sp = _fp;
368     }
369     else if (sender_cm->is_deopt_entry(_pc)) {
370       DEBUG_ONLY(verify_deopt_original_pc(sender_cm, _unextended_sp));
371     }
372     else if (sender_cm->is_method_handle_return(_pc)) {
373       _unextended_sp = _fp;
374     }
375   }
376 }
377 
378 //------------------------------------------------------------------------------
379 // frame::update_map_with_saved_link
380 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
381   // see x86 for comments
382   map->set_location(FP->as_VMReg(), (address) link_addr);
383 }
384 
385 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
386   // SP is the raw SP from the sender after adapter or interpreter
387   // extension.
388   intptr_t* sender_sp = this->sender_sp();
389 
390   // This is the sp before any possible extension (adapter/locals).
391   intptr_t* unextended_sp = interpreter_frame_sender_sp();
392 
393 #ifdef COMPILER2
394   if (map->update_map()) {
395     update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
396   }
397 #endif // COMPILER2
398 
399   return frame(sender_sp, unextended_sp, link(), sender_pc());
400 }
401 
402 template <bool stub>
403 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
404   assert(map != NULL, "map must be set");
405 
406   // frame owned by optimizing compiler
407   assert(_cb->frame_size() >= 0, "must have non-zero frame size");
408   intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
409   intptr_t* unextended_sp = sender_sp;
410 
411   address sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
412 
413   // This is the saved value of FP which may or may not really be an FP.
414   // It is only an FP if the sender is an interpreter frame (or C1?).
415   intptr_t** saved_fp_addr = (intptr_t**) (sender_sp - sender_sp_offset + link_offset);
416 
417   if (map->update_map()) {
418     // Tell GC to use argument oopmaps for some runtime stubs that need it.
419     // For C1, the runtime stub might not have oop maps, so set this flag
420     // outside of update_register_map.
421     map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
422     if (_cb->oop_maps() != NULL) {
423       OopMapSet::update_register_map(this, map);
424     }
425 
426     // Since the prolog does the save and restore of FP there is no oopmap
427     // for it so we must fill in its location as if there was an oopmap entry
428     // since if our caller was compiled code there could be live jvm state in it.
429     update_map_with_saved_link(map, saved_fp_addr);
430   }
431 
432   assert(sender_sp != sp(), "must have changed");
433   return frame(sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
434 }
435 
436 frame frame::sender(RegisterMap* map) const {
437   // Default is we done have to follow them. The sender_for_xxx will
438   // update it accordingly
439   map->set_include_argument_oops(false);
440 
441   if (is_entry_frame())       return sender_for_entry_frame(map);
442   if (is_interpreted_frame()) return sender_for_interpreter_frame(map);
443   assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
444 
445   if (_cb != NULL) {
446     return sender_for_compiled_frame<false>(map);
447   }
448 
449   assert(false, "should not be called for a C frame");
450   return frame();
451 }
452 
453 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
454   assert(is_interpreted_frame(), "Not an interpreted frame");
455   // These are reasonable sanity checks
456   if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
457     return false;
458   }
459   if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
460     return false;
461   }
462   if (fp() + interpreter_frame_initial_sp_offset < sp()) {
463     return false;
464   }
465   // These are hacks to keep us out of trouble.
466   // The problem with these is that they mask other problems
467   if (fp() <= sp()) {        // this attempts to deal with unsigned comparison above
468     return false;
469   }
470   // do some validation of frame elements
471 
472   // first the method
473 
474   Method* m = *interpreter_frame_method_addr();
475 
476   // validate the method we'd find in this potential sender
477   if (!Method::is_valid_method(m)) return false;
478 
479   // stack frames shouldn't be much larger than max_stack elements
480 
481   if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
482     return false;
483   }
484 
485   // validate bci/bcp
486 
487   address bcp = interpreter_frame_bcp();
488   if (m->validate_bci_from_bcp(bcp) < 0) {
489     return false;
490   }
491 
492   // validate ConstantPoolCache*
493   ConstantPoolCache* cp = *interpreter_frame_cache_addr();
494   if (MetaspaceObj::is_valid(cp) == false) return false;
495 
496   // validate locals
497 
498   address locals =  (address) *interpreter_frame_locals_addr();
499   return thread->is_in_stack_range_incl(locals, (address)fp());
500 }
501 
502 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
503   assert(is_interpreted_frame(), "interpreted frame expected");
504   Method* method = interpreter_frame_method();
505   BasicType type = method->result_type();
506 
507   intptr_t* res_addr;
508   if (method->is_native()) {
509     // Prior to calling into the runtime to report the method_exit both of
510     // the possible return value registers are saved.
511     // Return value registers are pushed to the native stack
512     res_addr = (intptr_t*)sp();
513 #ifdef __ABI_HARD__
514     // FP result is pushed onto a stack along with integer result registers
515     if (type == T_FLOAT || type == T_DOUBLE) {
516       res_addr += 2;
517     }
518 #endif // __ABI_HARD__
519   } else {
520     res_addr = (intptr_t*)interpreter_frame_tos_address();
521   }
522 
523   switch (type) {
524     case T_OBJECT  :
525     case T_ARRAY   : {
526       oop obj;
527       if (method->is_native()) {
528         obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
529       } else {
530         obj = *(oop*)res_addr;
531       }
532       assert(Universe::is_in_heap_or_null(obj), "sanity check");
533       *oop_result = obj;
534       break;
535     }
536     case T_BOOLEAN : value_result->z = *(jboolean*)res_addr; break;
537     case T_BYTE    : value_result->b = *(jbyte*)res_addr; break;
538     case T_CHAR    : value_result->c = *(jchar*)res_addr; break;
539     case T_SHORT   : value_result->s = *(jshort*)res_addr; break;
540     case T_INT     : value_result->i = *(jint*)res_addr; break;
541     case T_LONG    : value_result->j = *(jlong*)res_addr; break;
542     case T_FLOAT   : value_result->f = *(jfloat*)res_addr; break;
543     case T_DOUBLE  : value_result->d = *(jdouble*)res_addr; break;
544     case T_VOID    : /* Nothing to do */ break;
545     default        : ShouldNotReachHere();
546   }
547 
548   return type;
549 }
550 
551 template intptr_t* frame::interpreter_frame_tos_at<false>(jint offset) const;
552 template intptr_t* frame::interpreter_frame_tos_at<true >(jint offset) const;
553 
554 template <bool relative>
555 inline intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
556   int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
557   return &interpreter_frame_tos_address()[index];
558 }
559 
560 #ifndef PRODUCT
561 
562 #define DESCRIBE_FP_OFFSET(name) \
563   values.describe(frame_no, fp() + frame::name##_offset, #name)
564 
565 void frame::describe_pd(FrameValues& values, int frame_no) {
566   if (is_interpreted_frame()) {
567     DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
568     DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
569     DESCRIBE_FP_OFFSET(interpreter_frame_method);
570     DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
571     DESCRIBE_FP_OFFSET(interpreter_frame_cache);
572     DESCRIBE_FP_OFFSET(interpreter_frame_locals);
573     DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
574     DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
575   }
576 }
577 
578 // This is a generic constructor which is only used by pns() in debug.cpp.
579 frame::frame(void* sp, void* fp, void* pc) {
580   init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
581 }
582 
583 void frame::describe_top_pd(FrameValues& values) {
584   Unimplemented();
585 }
586 #endif
587 
588 intptr_t *frame::initial_deoptimization_info() {
589   // used to reset the saved FP
590   return fp();
591 }
592 
593 intptr_t* frame::real_fp() const {
594   if (is_entry_frame()) {
595     // Work-around: FP (currently) does not conform to the ABI for entry
596     // frames (see generate_call_stub). Might be worth fixing as another CR.
597     // Following code assumes (and asserts) this has not yet been fixed.
598     assert(frame::entry_frame_call_wrapper_offset == 0, "adjust this code");
599     intptr_t* new_fp = fp();
600     new_fp += 5; // saved R0,R1,R2,R4,R10
601 #ifndef __SOFTFP__
602     new_fp += 8*2; // saved D8..D15
603 #endif
604     return new_fp;
605   }
606   if (_cb != NULL) {
607     // use the frame size if valid
608     int size = _cb->frame_size();
609     if (size > 0) {
610       return unextended_sp() + size;
611     }
612   }
613   // else rely on fp()
614   assert(! is_compiled_frame(), "unknown compiled frame size");
615   return fp();
616 }
--- EOF ---