1 /*
2 * Copyright (c) 2008, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "interpreter/interpreter.hpp"
27 #include "memory/resourceArea.hpp"
28 #include "memory/universe.hpp"
29 #include "oops/markWord.hpp"
30 #include "oops/method.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/frame.inline.hpp"
33 #include "runtime/handles.inline.hpp"
34 #include "runtime/javaCalls.hpp"
35 #include "runtime/monitorChunk.hpp"
36 #include "runtime/os.inline.hpp"
37 #include "runtime/signature.hpp"
38 #include "runtime/stubCodeGenerator.hpp"
39 #include "runtime/stubRoutines.hpp"
40 #include "vmreg_arm.inline.hpp"
41 #ifdef COMPILER1
42 #include "c1/c1_Runtime1.hpp"
43 #include "runtime/vframeArray.hpp"
44 #endif
45 #include "prims/methodHandles.hpp"
46
47 #ifdef ASSERT
48 void RegisterMap::check_location_valid() {
49 }
50 #endif
51
52
53 // Profiling/safepoint support
54
55 bool frame::safe_for_sender(JavaThread *thread) {
56 address sp = (address)_sp;
57 address fp = (address)_fp;
58 address unextended_sp = (address)_unextended_sp;
59
60 // consider stack guards when trying to determine "safe" stack pointers
61 // sp must be within the usable part of the stack (not in guards)
62 if (!thread->is_in_usable_stack(sp)) {
63 return false;
64 }
65
66 bool unextended_sp_safe = (unextended_sp != NULL &&
67 (unextended_sp < thread->stack_base()) &&
68 (unextended_sp >= sp));
69 if (!unextended_sp_safe) {
70 return false;
71 }
72
73 // We know sp/unextended_sp are safe. Only fp is questionable here.
74
75 bool fp_safe = (fp != NULL &&
76 (fp < thread->stack_base()) &&
77 fp >= sp);
78
79 if (_cb != NULL ) {
80
81 // First check if frame is complete and tester is reliable
82 // Unfortunately we can only check frame complete for runtime stubs and nmethod
83 // other generic buffer blobs are more problematic so we just assume they are
84 // ok. adapter blobs never have a frame complete and are never ok.
85
86 if (!_cb->is_frame_complete_at(_pc)) {
87 if (_cb->is_compiled() || _cb->is_adapter_blob() || _cb->is_runtime_stub()) {
88 return false;
89 }
90 }
91
92 // Could just be some random pointer within the codeBlob
93 if (!_cb->code_contains(_pc)) {
94 return false;
95 }
96
97 // Entry frame checks
98 if (is_entry_frame()) {
99 // an entry frame must have a valid fp.
100 return fp_safe && is_entry_frame_valid(thread);
101 }
102
103 intptr_t* sender_sp = NULL;
104 address sender_pc = NULL;
105
106 if (is_interpreted_frame()) {
107 // fp must be safe
108 if (!fp_safe) {
109 return false;
110 }
111
112 sender_pc = (address) this->fp()[return_addr_offset];
113 sender_sp = (intptr_t*) addr_at(sender_sp_offset);
114
115 } else {
116 // must be some sort of compiled/runtime frame
117 // fp does not have to be safe (although it could be check for c1?)
118
119 sender_sp = _unextended_sp + _cb->frame_size();
120 // Is sender_sp safe?
121 if ((address)sender_sp >= thread->stack_base()) {
122 return false;
123 }
124 // With our calling conventions, the return_address should
125 // end up being the word on the stack
126 sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
127 }
128
129 // We must always be able to find a recognizable pc
130 CodeBlob* sender_blob = CodeCache::find_blob_unsafe(sender_pc);
131 if (sender_pc == NULL || sender_blob == NULL) {
132 return false;
133 }
134
135
136 // If the potential sender is the interpreter then we can do some more checking
137 if (Interpreter::contains(sender_pc)) {
138
139 // FP is always saved in a recognizable place in any code we generate. However
140 // only if the sender is interpreted/call_stub (c1 too?) are we certain that the saved FP
141 // is really a frame pointer.
142
143 intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
144 bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
145
146 if (!saved_fp_safe) {
147 return false;
148 }
149
150 // construct the potential sender
151
152 frame sender(sender_sp, saved_fp, sender_pc);
153
154 return sender.is_interpreted_frame_valid(thread);
155 }
156
157 if (sender_blob->is_zombie() || sender_blob->is_unloaded()) {
158 return false;
159 }
160
161 // Could just be some random pointer within the codeBlob
162 if (!sender_blob->code_contains(sender_pc)) {
163 return false;
164 }
165
166 // We should never be able to see an adapter if the current frame is something from code cache
167 if (sender_blob->is_adapter_blob()) {
168 return false;
169 }
170
171 // Could be the call_stub
172 if (StubRoutines::returns_to_call_stub(sender_pc)) {
173 intptr_t *saved_fp = (intptr_t*)*(sender_sp - frame::sender_sp_offset + link_offset);
174 bool saved_fp_safe = ((address)saved_fp < thread->stack_base()) && (saved_fp > sender_sp);
175
176 if (!saved_fp_safe) {
177 return false;
178 }
179
180 // construct the potential sender
181
182 frame sender(sender_sp, saved_fp, sender_pc);
183
184 // Validate the JavaCallWrapper an entry frame must have
185 address jcw = (address)sender.entry_frame_call_wrapper();
186
187 bool jcw_safe = (jcw < thread->stack_base()) && (jcw > (address)sender.fp());
188
189 return jcw_safe;
190 }
191
192 // If the frame size is 0 something (or less) is bad because every nmethod has a non-zero frame size
193 // because the return address counts against the callee's frame.
194
195 if (sender_blob->frame_size() <= 0) {
196 assert(!sender_blob->is_compiled(), "should count return address at least");
197 return false;
198 }
199
200 // We should never be able to see anything here except an nmethod. If something in the
201 // code cache (current frame) is called by an entity within the code cache that entity
202 // should not be anything but the call stub (already covered), the interpreter (already covered)
203 // or an nmethod.
204
205 if (!sender_blob->is_compiled()) {
206 return false;
207 }
208
209 // Could put some more validation for the potential non-interpreted sender
210 // frame we'd create by calling sender if I could think of any. Wait for next crash in forte...
211
212 // One idea is seeing if the sender_pc we have is one that we'd expect to call to current cb
213
214 // We've validated the potential sender that would be created
215 return true;
216 }
217
218 // Must be native-compiled frame. Since sender will try and use fp to find
219 // linkages it must be safe
220
221 if (!fp_safe) {
222 return false;
223 }
224
225 // Will the pc we fetch be non-zero (which we'll find at the oldest frame)
226
227 if ((address) this->fp()[return_addr_offset] == NULL) return false;
228
229
230 // could try and do some more potential verification of native frame if we could think of some...
231
232 return true;
233 }
234
235
236 void frame::patch_pc(Thread* thread, address pc) {
237 address* pc_addr = &((address *)sp())[-sender_sp_offset+return_addr_offset];
238 if (TracePcPatching) {
239 tty->print_cr("patch_pc at address" INTPTR_FORMAT " [" INTPTR_FORMAT " -> " INTPTR_FORMAT "] ",
240 p2i(pc_addr), p2i(*pc_addr), p2i(pc));
241 }
242 *pc_addr = pc;
243 _cb = CodeCache::find_blob(pc);
244 address original_pc = CompiledMethod::get_deopt_original_pc(this);
245 if (original_pc != NULL) {
246 assert(original_pc == _pc, "expected original PC to be stored before patching");
247 _deopt_state = is_deoptimized;
248 // leave _pc as is
249 } else {
250 _deopt_state = not_deoptimized;
251 _pc = pc;
252 }
253 }
254
255 bool frame::is_interpreted_frame() const {
256 return Interpreter::contains(pc());
257 }
258
259 int frame::frame_size(RegisterMap* map) const {
260 frame sender = this->sender(map);
261 return sender.sp() - sp();
262 }
263
264 intptr_t* frame::entry_frame_argument_at(int offset) const {
265 assert(is_entry_frame(), "entry frame expected");
266 // convert offset to index to deal with tsi
267 int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
268 // Entry frame's arguments are always in relation to unextended_sp()
269 return &unextended_sp()[index];
270 }
271
272 // sender_sp
273 intptr_t* frame::interpreter_frame_sender_sp() const {
274 assert(is_interpreted_frame(), "interpreted frame expected");
275 return (intptr_t*) at(interpreter_frame_sender_sp_offset);
276 }
277
278 void frame::set_interpreter_frame_sender_sp(intptr_t* sender_sp) {
279 assert(is_interpreted_frame(), "interpreted frame expected");
280 ptr_at_put(interpreter_frame_sender_sp_offset, (intptr_t) sender_sp);
281 }
282
283
284 // monitor elements
285
286 BasicObjectLock* frame::interpreter_frame_monitor_begin() const {
287 return (BasicObjectLock*) addr_at(interpreter_frame_monitor_block_bottom_offset);
288 }
289
290 BasicObjectLock* frame::interpreter_frame_monitor_end() const {
291 BasicObjectLock* result = (BasicObjectLock*) *addr_at(interpreter_frame_monitor_block_top_offset);
292 // make sure the pointer points inside the frame
293 assert((intptr_t) fp() > (intptr_t) result, "result must < than frame pointer");
294 assert((intptr_t) sp() <= (intptr_t) result, "result must >= than stack pointer");
295 return result;
296 }
297
298 void frame::interpreter_frame_set_monitor_end(BasicObjectLock* value) {
299 *((BasicObjectLock**)addr_at(interpreter_frame_monitor_block_top_offset)) = value;
300 }
301
302
303 // Used by template based interpreter deoptimization
304 void frame::interpreter_frame_set_last_sp(intptr_t* sp) {
305 *((intptr_t**)addr_at(interpreter_frame_last_sp_offset)) = sp;
306 }
307
308
309 frame frame::sender_for_entry_frame(RegisterMap* map) const {
310 assert(map != NULL, "map must be set");
311 // Java frame called from C; skip all C frames and return top C
312 // frame of that chunk as the sender
313 JavaFrameAnchor* jfa = entry_frame_call_wrapper()->anchor();
314 assert(!entry_frame_is_first(), "next Java fp must be non zero");
315 assert(jfa->last_Java_sp() > sp(), "must be above this frame on stack");
316 map->clear();
317 assert(map->include_argument_oops(), "should be set by clear");
318 if (jfa->last_Java_pc() != NULL) {
319 frame fr(jfa->last_Java_sp(), jfa->last_Java_fp(), jfa->last_Java_pc());
320 return fr;
321 }
322 frame fr(jfa->last_Java_sp(), jfa->last_Java_fp());
323 return fr;
324 }
325
326 //------------------------------------------------------------------------------
327 // frame::verify_deopt_original_pc
328 //
329 // Verifies the calculated original PC of a deoptimization PC for the
330 // given unextended SP. The unextended SP might also be the saved SP
331 // for MethodHandle call sites.
332 #ifdef ASSERT
333 void frame::verify_deopt_original_pc(CompiledMethod* nm, intptr_t* unextended_sp, bool is_method_handle_return) {
334 frame fr;
335
336 // This is ugly but it's better than to change {get,set}_original_pc
337 // to take an SP value as argument. And it's only a debugging
338 // method anyway.
339 fr._unextended_sp = unextended_sp;
340
341 address original_pc = nm->get_original_pc(&fr);
342 assert(nm->insts_contains_inclusive(original_pc),
343 "original PC must be in the main code section of the the compiled method (or must be immediately following it)");
344 assert(nm->is_method_handle_return(original_pc) == is_method_handle_return, "must be");
345 }
346 #endif
347
348 //------------------------------------------------------------------------------
349 // frame::adjust_unextended_sp
350 void frame::adjust_unextended_sp() {
351 // same as on x86
352
353 // If we are returning to a compiled MethodHandle call site, the
354 // saved_fp will in fact be a saved value of the unextended SP. The
355 // simplest way to tell whether we are returning to such a call site
356 // is as follows:
357
358 CompiledMethod* sender_cm = (_cb == NULL) ? NULL : _cb->as_compiled_method_or_null();
359 if (sender_cm != NULL) {
360 // If the sender PC is a deoptimization point, get the original
361 // PC. For MethodHandle call site the unextended_sp is stored in
362 // saved_fp.
363 if (sender_cm->is_deopt_mh_entry(_pc)) {
364 DEBUG_ONLY(verify_deopt_mh_original_pc(sender_cm, _fp));
365 _unextended_sp = _fp;
366 }
367 else if (sender_cm->is_deopt_entry(_pc)) {
368 DEBUG_ONLY(verify_deopt_original_pc(sender_cm, _unextended_sp));
369 }
370 else if (sender_cm->is_method_handle_return(_pc)) {
371 _unextended_sp = _fp;
372 }
373 }
374 }
375
376 //------------------------------------------------------------------------------
377 // frame::update_map_with_saved_link
378 void frame::update_map_with_saved_link(RegisterMap* map, intptr_t** link_addr) {
379 // see x86 for comments
380 map->set_location(FP->as_VMReg(), (address) link_addr);
381 }
382
383 frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
384 // SP is the raw SP from the sender after adapter or interpreter
385 // extension.
386 intptr_t* sender_sp = this->sender_sp();
387
388 // This is the sp before any possible extension (adapter/locals).
389 intptr_t* unextended_sp = interpreter_frame_sender_sp();
390
391 #ifdef COMPILER2
392 if (map->update_map()) {
393 update_map_with_saved_link(map, (intptr_t**) addr_at(link_offset));
394 }
395 #endif // COMPILER2
396
397 return frame(sender_sp, unextended_sp, link(), sender_pc());
398 }
399
400 frame frame::sender_for_compiled_frame(RegisterMap* map) const {
401 assert(map != NULL, "map must be set");
402
403 // frame owned by optimizing compiler
404 assert(_cb->frame_size() >= 0, "must have non-zero frame size");
405 intptr_t* sender_sp = unextended_sp() + _cb->frame_size();
406 intptr_t* unextended_sp = sender_sp;
407
408 address sender_pc = (address) *(sender_sp - sender_sp_offset + return_addr_offset);
409
410 // This is the saved value of FP which may or may not really be an FP.
411 // It is only an FP if the sender is an interpreter frame (or C1?).
412 intptr_t** saved_fp_addr = (intptr_t**) (sender_sp - sender_sp_offset + link_offset);
413
414 if (map->update_map()) {
415 // Tell GC to use argument oopmaps for some runtime stubs that need it.
416 // For C1, the runtime stub might not have oop maps, so set this flag
417 // outside of update_register_map.
418 map->set_include_argument_oops(_cb->caller_must_gc_arguments(map->thread()));
419 if (_cb->oop_maps() != NULL) {
420 OopMapSet::update_register_map(this, map);
421 }
422
423 // Since the prolog does the save and restore of FP there is no oopmap
424 // for it so we must fill in its location as if there was an oopmap entry
425 // since if our caller was compiled code there could be live jvm state in it.
426 update_map_with_saved_link(map, saved_fp_addr);
427 }
428
429 assert(sender_sp != sp(), "must have changed");
430 return frame(sender_sp, unextended_sp, *saved_fp_addr, sender_pc);
431 }
432
433 frame frame::sender(RegisterMap* map) const {
434 // Default is we done have to follow them. The sender_for_xxx will
435 // update it accordingly
436 map->set_include_argument_oops(false);
437
438 if (is_entry_frame()) return sender_for_entry_frame(map);
439 if (is_interpreted_frame()) return sender_for_interpreter_frame(map);
440 assert(_cb == CodeCache::find_blob(pc()),"Must be the same");
441
442 if (_cb != NULL) {
443 return sender_for_compiled_frame(map);
444 }
445
446 assert(false, "should not be called for a C frame");
447 return frame();
448 }
449
450 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
451 assert(is_interpreted_frame(), "Not an interpreted frame");
452 // These are reasonable sanity checks
453 if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
454 return false;
455 }
456 if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
457 return false;
458 }
459 if (fp() + interpreter_frame_initial_sp_offset < sp()) {
460 return false;
461 }
462 // These are hacks to keep us out of trouble.
463 // The problem with these is that they mask other problems
464 if (fp() <= sp()) { // this attempts to deal with unsigned comparison above
465 return false;
466 }
467 // do some validation of frame elements
468
469 // first the method
470
471 Method* m = *interpreter_frame_method_addr();
472
473 // validate the method we'd find in this potential sender
474 if (!Method::is_valid_method(m)) return false;
475
476 // stack frames shouldn't be much larger than max_stack elements
477
478 if (fp() - sp() > 1024 + m->max_stack()*Interpreter::stackElementSize) {
479 return false;
480 }
481
482 // validate bci/bcp
483
484 address bcp = interpreter_frame_bcp();
485 if (m->validate_bci_from_bcp(bcp) < 0) {
486 return false;
487 }
488
489 // validate ConstantPoolCache*
490 ConstantPoolCache* cp = *interpreter_frame_cache_addr();
491 if (MetaspaceObj::is_valid(cp) == false) return false;
492
493 // validate locals
494
495 address locals = (address) *interpreter_frame_locals_addr();
496
497 if (locals >= thread->stack_base() || locals < (address) fp()) return false;
498
499 // We'd have to be pretty unlucky to be mislead at this point
500
501 return true;
502 }
503
504 BasicType frame::interpreter_frame_result(oop* oop_result, jvalue* value_result) {
505 assert(is_interpreted_frame(), "interpreted frame expected");
506 Method* method = interpreter_frame_method();
507 BasicType type = method->result_type();
508
509 intptr_t* res_addr;
510 if (method->is_native()) {
511 // Prior to calling into the runtime to report the method_exit both of
512 // the possible return value registers are saved.
513 // Return value registers are pushed to the native stack
514 res_addr = (intptr_t*)sp();
515 #ifdef __ABI_HARD__
516 // FP result is pushed onto a stack along with integer result registers
517 if (type == T_FLOAT || type == T_DOUBLE) {
518 res_addr += 2;
519 }
520 #endif // __ABI_HARD__
521 } else {
522 res_addr = (intptr_t*)interpreter_frame_tos_address();
523 }
524
525 switch (type) {
526 case T_OBJECT :
527 case T_ARRAY : {
528 oop obj;
529 if (method->is_native()) {
530 obj = cast_to_oop(at(interpreter_frame_oop_temp_offset));
531 } else {
532 obj = *(oop*)res_addr;
533 }
534 assert(obj == NULL || Universe::heap()->is_in(obj), "sanity check");
535 *oop_result = obj;
536 break;
537 }
538 case T_BOOLEAN : value_result->z = *(jboolean*)res_addr; break;
539 case T_BYTE : value_result->b = *(jbyte*)res_addr; break;
540 case T_CHAR : value_result->c = *(jchar*)res_addr; break;
541 case T_SHORT : value_result->s = *(jshort*)res_addr; break;
542 case T_INT : value_result->i = *(jint*)res_addr; break;
543 case T_LONG : value_result->j = *(jlong*)res_addr; break;
544 case T_FLOAT : value_result->f = *(jfloat*)res_addr; break;
545 case T_DOUBLE : value_result->d = *(jdouble*)res_addr; break;
546 case T_VOID : /* Nothing to do */ break;
547 default : ShouldNotReachHere();
548 }
549
550 return type;
551 }
552
553
554 intptr_t* frame::interpreter_frame_tos_at(jint offset) const {
555 int index = (Interpreter::expr_offset_in_bytes(offset)/wordSize);
556 return &interpreter_frame_tos_address()[index];
557 }
558
559 #ifndef PRODUCT
560
561 #define DESCRIBE_FP_OFFSET(name) \
562 values.describe(frame_no, fp() + frame::name##_offset, #name)
563
564 void frame::describe_pd(FrameValues& values, int frame_no) {
565 if (is_interpreted_frame()) {
566 DESCRIBE_FP_OFFSET(interpreter_frame_sender_sp);
567 DESCRIBE_FP_OFFSET(interpreter_frame_last_sp);
568 DESCRIBE_FP_OFFSET(interpreter_frame_method);
569 DESCRIBE_FP_OFFSET(interpreter_frame_mdp);
570 DESCRIBE_FP_OFFSET(interpreter_frame_cache);
571 DESCRIBE_FP_OFFSET(interpreter_frame_locals);
572 DESCRIBE_FP_OFFSET(interpreter_frame_bcp);
573 DESCRIBE_FP_OFFSET(interpreter_frame_initial_sp);
574 }
575 }
576
577 // This is a generic constructor which is only used by pns() in debug.cpp.
578 frame::frame(void* sp, void* fp, void* pc) {
579 init((intptr_t*)sp, (intptr_t*)fp, (address)pc);
580 }
581
582 void frame::pd_ps() {}
583 #endif
584
585 intptr_t *frame::initial_deoptimization_info() {
586 // used to reset the saved FP
587 return fp();
588 }
589
590 intptr_t* frame::real_fp() const {
591 if (is_entry_frame()) {
592 // Work-around: FP (currently) does not conform to the ABI for entry
593 // frames (see generate_call_stub). Might be worth fixing as another CR.
594 // Following code assumes (and asserts) this has not yet been fixed.
595 assert(frame::entry_frame_call_wrapper_offset == 0, "adjust this code");
596 intptr_t* new_fp = fp();
597 new_fp += 5; // saved R0,R1,R2,R4,R10
598 #ifndef __SOFTFP__
599 new_fp += 8*2; // saved D8..D15
600 #endif
601 return new_fp;
602 }
603 if (_cb != NULL) {
604 // use the frame size if valid
605 int size = _cb->frame_size();
606 if (size > 0) {
607 return unextended_sp() + size;
608 }
609 }
610 // else rely on fp()
611 assert(! is_compiled_frame(), "unknown compiled frame size");
612 return fp();
613 }