Line data Source code
1 : /* src/vm/jit/x86_64/patcher.cpp - x86_64 code patching functions
2 :
3 : Copyright (C) 1996-2013
4 : CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
5 :
6 : This file is part of CACAO.
7 :
8 : This program is free software; you can redistribute it and/or
9 : modify it under the terms of the GNU General Public License as
10 : published by the Free Software Foundation; either version 2, or (at
11 : your option) any later version.
12 :
13 : This program is distributed in the hope that it will be useful, but
14 : WITHOUT ANY WARRANTY; without even the implied warranty of
15 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 : General Public License for more details.
17 :
18 : You should have received a copy of the GNU General Public License
19 : along with this program; if not, write to the Free Software
20 : Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 : 02110-1301, USA.
22 :
23 : */
24 :
25 :
26 : #include "config.h"
27 :
28 : #include <stdint.h>
29 :
30 : #include "vm/types.hpp"
31 :
32 : #include "vm/jit/x86_64/codegen.hpp"
33 : #include "vm/jit/x86_64/md.hpp"
34 :
35 : #include "mm/memory.hpp"
36 :
37 : #include "native/native.hpp"
38 :
39 : #include "vm/jit/builtin.hpp"
40 : #include "vm/class.hpp"
41 : #include "vm/field.hpp"
42 : #include "vm/initialize.hpp"
43 : #include "vm/options.hpp"
44 : #include "vm/resolve.hpp"
45 :
46 : #include "vm/jit/patcher-common.hpp"
47 :
48 :
49 : /* patcher_patch_code **********************************************************
50 :
51 : Just patches back the original machine code.
52 :
53 : *******************************************************************************/
54 :
55 71128 : void patcher_patch_code(patchref_t *pr)
56 : {
57 71128 : *((uint16_t*) pr->mpc) = (uint16_t) pr->mcode;
58 71128 : md_icacheflush((void*) pr->mpc, PATCHER_CALL_SIZE);
59 71128 : }
60 :
61 12390 : static int32_t *patch_checked_location(int32_t *p, int32_t val)
62 : {
63 12390 : assert(*p == 0);
64 : // verify that it's aligned
65 12390 : assert((((uintptr_t) p) & (4-1)) == 0);
66 12390 : *p = val;
67 12390 : return p;
68 : }
69 :
70 667 : static void checked_icache_flush(void *addr, int nbytes, int32_t *check_loc)
71 : {
72 667 : assert((int8_t*) addr + nbytes - sizeof(int32_t) >= (int8_t*) check_loc);
73 667 : md_icacheflush(addr, nbytes);
74 667 : }
75 :
76 : /**
77 : * Check if the trap instruction at the given PC is valid.
78 : *
79 : * @param pc Program counter.
80 : *
81 : * @return true if valid, false otherwise.
82 : */
83 71147 : bool patcher_is_valid_trap_instruction_at(void* pc)
84 : {
85 71147 : uint16_t mcode = *((uint16_t*) pc);
86 :
87 : // Check for the undefined instruction we use.
88 71147 : return (mcode == 0x0b0f);
89 : }
90 :
91 : /**
92 : * Overwrites the MFENCE instruction at the indicated address with a 3-byte
93 : * NOP. The MFENCE instruction is not allowed to cross a (4-byte) word
94 : * boundary.
95 : *
96 : * @param pc Program counter.
97 : */
98 1637 : static void patch_out_mfence(void *pc)
99 : {
100 1637 : uint32_t *p = (uint32_t*) (((uintptr_t) pc) & ~3);
101 :
102 1637 : assert((((uintptr_t) pc) & 3) < 2);
103 1637 : if (((uintptr_t) pc) & 1)
104 4 : *p = (*p & 0x000000ff) | 0x001f0f00;
105 : else
106 1633 : *p = (*p & 0xff000000) | 0x00001f0f;
107 :
108 1637 : md_icacheflush(p, 4);
109 1637 : }
110 :
111 : /* patcher_resolve_classref_to_classinfo ***************************************
112 :
113 : ACONST:
114 :
115 : <patched call position>
116 : 48 bf a0 f0 92 00 00 00 00 00 mov $0x92f0a0,%rdi
117 :
118 : MULTIANEWARRAY:
119 :
120 : <patched call position>
121 : 48 be 30 40 b2 00 00 00 00 00 mov $0xb24030,%rsi
122 : 48 89 e2 mov %rsp,%rdx
123 : 48 b8 7c 96 4b 00 00 00 00 00 mov $0x4b967c,%rax
124 : 48 ff d0 callq *%rax
125 :
126 : ARRAYCHECKCAST:
127 :
128 : <patched call position>
129 : 48 be b8 3f b2 00 00 00 00 00 mov $0xb23fb8,%rsi
130 : 48 b8 00 00 00 00 00 00 00 00 mov $0x0,%rax
131 : 48 ff d0 callq *%rax
132 :
133 : *******************************************************************************/
134 :
135 14079 : bool patcher_resolve_classref_to_classinfo(patchref_t *pr)
136 : {
137 14079 : constant_classref* cr = (constant_classref*) pr->ref;
138 14079 : uintptr_t* datap = (uintptr_t*) pr->datap;
139 :
140 : // Resolve the class.
141 14079 : classinfo* c = resolve_classref_eager(cr);
142 :
143 14079 : if (c == NULL)
144 1 : return false;
145 :
146 : // Patch the class.
147 14078 : *datap = (uintptr_t) c;
148 :
149 : // Synchronize data cache.
150 14078 : md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P);
151 :
152 : // Patch back the original code.
153 14078 : patcher_patch_code(pr);
154 :
155 14078 : return true;
156 : }
157 :
158 :
159 : /* patcher_resolve_classref_to_vftbl *******************************************
160 :
161 : CHECKCAST (class):
162 : INSTANCEOF (class):
163 :
164 : <patched call position>
165 :
166 : *******************************************************************************/
167 :
168 556 : bool patcher_resolve_classref_to_vftbl(patchref_t *pr)
169 : {
170 556 : constant_classref* cr = (constant_classref*) pr->ref;
171 556 : uintptr_t* datap = (uintptr_t*) pr->datap;
172 :
173 : // Resolve the field.
174 556 : classinfo* c = resolve_classref_eager(cr);
175 :
176 556 : if (c == NULL)
177 0 : return false;
178 :
179 : // Patch super class' vftbl.
180 556 : *datap = (uintptr_t) c->vftbl;
181 :
182 : // Synchronize data cache.
183 556 : md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P);
184 :
185 : // Patch back the original code.
186 556 : patcher_patch_code(pr);
187 :
188 556 : return true;
189 : }
190 :
191 :
192 : /* patcher_resolve_classref_to_flags *******************************************
193 :
194 : CHECKCAST/INSTANCEOF:
195 :
196 : <patched call position>
197 :
198 : *******************************************************************************/
199 :
200 599 : bool patcher_resolve_classref_to_flags(patchref_t *pr)
201 : {
202 599 : constant_classref* cr = (constant_classref*) pr->ref;
203 : /* int32_t* datap = (int32_t*) pr->datap; */
204 599 : uint8_t* ra = (uint8_t*) pr->mpc;
205 :
206 : // Resolve the field.
207 599 : classinfo* c = resolve_classref_eager(cr);
208 :
209 599 : if (c == NULL)
210 0 : return false;
211 :
212 599 : ra += PATCHER_CALL_SIZE;
213 599 : ra += PATCH_ALIGNMENT((uintptr_t) ra, 2, sizeof(int32_t));
214 :
215 : // Patch class flags.
216 : /* *datap = c->flags; */
217 599 : patch_checked_location((int32_t*) (ra + 2), c->flags);
218 :
219 : // Synchronize data cache.
220 : /* md_dcacheflush(datap, sizeof(int32_t)); */
221 599 : md_icacheflush(ra + 2, sizeof(int32_t));
222 :
223 : // Patch back the original code.
224 599 : patcher_patch_code(pr);
225 :
226 599 : return true;
227 : }
228 :
229 :
230 : /* patcher_get_putstatic *******************************************************
231 :
232 : Machine code:
233 :
234 : <patched call position>
235 : 4d 8b 15 86 fe ff ff mov -378(%rip),%r10
236 : 49 8b 32 mov (%r10),%rsi
237 :
238 : *******************************************************************************/
239 :
240 18169 : bool patcher_get_putstatic(patchref_t *pr)
241 : {
242 18169 : unresolved_field* uf = (unresolved_field*) pr->ref;
243 18169 : uintptr_t* datap = (uintptr_t*) pr->datap;
244 18169 : uint8_t* ra = (uint8_t*) pr->mpc;
245 :
246 : // Resolve the field.
247 18169 : fieldinfo* fi = resolve_field_eager(uf);
248 :
249 18169 : if (fi == NULL)
250 0 : return false;
251 :
252 18169 : ra += PATCHER_CALL_SIZE;
253 :
254 : // Check if the field's class is initialized/
255 18169 : if (!(fi->clazz->state & CLASS_INITIALIZED))
256 2701 : if (!initialize_class(fi->clazz))
257 2 : return false;
258 :
259 : // Patch the field value's address.
260 18167 : *datap = (uintptr_t) fi->value;
261 :
262 18167 : if (pr->disp_mb && !(fi->flags & ACC_VOLATILE))
263 1339 : patch_out_mfence(ra + pr->disp_mb - 2);
264 :
265 : // Synchronize data cache.
266 18167 : md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P);
267 :
268 : // Patch back the original code.
269 18167 : patcher_patch_code(pr);
270 :
271 18167 : return true;
272 : }
273 :
274 :
275 : /* patcher_get_putfield ********************************************************
276 :
277 : Machine code:
278 :
279 : <patched call position>
280 : 45 8b 8f 00 00 00 00 mov 0x0(%r15),%r9d
281 :
282 : *******************************************************************************/
283 :
284 630 : bool patcher_get_putfield(patchref_t *pr)
285 : {
286 630 : uint8_t* pc = (uint8_t*) pr->mpc;
287 630 : unresolved_field* uf = (unresolved_field*) pr->ref;
288 :
289 : // Resolve the field.
290 630 : fieldinfo* fi = resolve_field_eager(uf);
291 :
292 630 : if (fi == NULL)
293 1 : return false;
294 :
295 629 : pc += PATCHER_CALL_SIZE;
296 :
297 629 : int disp = -sizeof(int32_t) + pr->patch_align;
298 629 : patch_checked_location((int32_t*) (pc + disp), fi->offset);
299 :
300 629 : if (pr->disp_mb && !(fi->flags & ACC_VOLATILE))
301 277 : patch_out_mfence(pc + pr->disp_mb - 2);
302 :
303 : // Synchronize instruction cache.
304 629 : md_icacheflush(pc, disp + sizeof(int32_t));
305 :
306 : // Patch back the original code.
307 629 : patcher_patch_code(pr);
308 :
309 629 : return true;
310 : }
311 :
312 :
313 : /* patcher_putfieldconst *******************************************************
314 :
315 : Machine code:
316 :
317 : <patched call position>
318 : 41 c7 85 00 00 00 00 7b 00 00 00 movl $0x7b,0x0(%r13)
319 :
320 : *******************************************************************************/
321 :
322 22 : bool patcher_putfieldconst(patchref_t *pr)
323 : {
324 22 : uint8_t* pc = (uint8_t*) pr->mpc;
325 22 : unresolved_field* uf = (unresolved_field*) pr->ref;
326 :
327 : // Resolve the field.
328 22 : fieldinfo* fi = resolve_field_eager(uf);
329 :
330 22 : if (fi == NULL)
331 1 : return false;
332 :
333 21 : pc += PATCHER_CALL_SIZE;
334 :
335 21 : int disp = -2*sizeof(int32_t) + pr->patch_align;
336 21 : patch_checked_location((int32_t*) (pc + disp), fi->offset);
337 :
338 21 : if (pr->disp_mb && !(fi->flags & ACC_VOLATILE))
339 21 : patch_out_mfence(pc + pr->disp_mb - 2);
340 :
341 : // Synchronize instruction cache.
342 21 : md_icacheflush(pc, disp + sizeof(int32_t));
343 :
344 : // Patch back the original code.
345 21 : patcher_patch_code(pr);
346 :
347 21 : return true;
348 : }
349 :
350 :
351 : /* patcher_invokestatic_special ************************************************
352 :
353 : Machine code:
354 :
355 : <patched call position>
356 : 49 ba 00 00 00 00 00 00 00 00 mov $0x0,%r10
357 : 49 ff d2 callq *%r10
358 :
359 : *******************************************************************************/
360 :
361 22894 : bool patcher_invokestatic_special(patchref_t *pr)
362 : {
363 22894 : unresolved_method* um = (unresolved_method*) pr->ref;
364 22894 : uintptr_t* datap = (uintptr_t*) pr->datap;
365 :
366 : // Resolve the method.
367 22894 : methodinfo* m = resolve_method_eager(um);
368 :
369 22894 : if (m == NULL)
370 0 : return false;
371 :
372 : // Patch stubroutine.
373 22894 : *datap = (uintptr_t) m->stubroutine;
374 :
375 : // Synchronize data cache.
376 22894 : md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P);
377 :
378 : // Patch back the original code.
379 22894 : patcher_patch_code(pr);
380 :
381 22894 : return true;
382 : }
383 :
384 :
385 : /* patcher_invokevirtual *******************************************************
386 :
387 : Machine code:
388 :
389 : <patched call position>
390 : 4c 8b 17 mov (%rdi),%r10
391 : 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
392 : 48 ff d0 callq *%rax
393 :
394 : *******************************************************************************/
395 :
396 9812 : bool patcher_invokevirtual(patchref_t *pr)
397 : {
398 9812 : uint8_t* pc = (uint8_t*) pr->mpc;
399 9812 : unresolved_method* um = (unresolved_method*) pr->ref;
400 :
401 : // Resovlve the method.
402 9812 : methodinfo* m = resolve_method_eager(um);
403 :
404 9812 : if (m == NULL)
405 5 : return false;
406 :
407 9807 : pc += PATCHER_CALL_SIZE;
408 9807 : pc += PATCH_ALIGNMENT((uintptr_t) pc, 6, sizeof(int32_t));
409 :
410 : // Patch vftbl index.
411 9807 : patch_checked_location((int32_t*) (pc + 6), (int32_t) (OFFSET(vftbl_t, table[0]) + sizeof(methodptr) * m->vftblindex));
412 :
413 : // Synchronize instruction cache.
414 9807 : md_icacheflush(pc + 3 + 3, SIZEOF_VOID_P);
415 :
416 : // Patch back the original code.
417 9807 : patcher_patch_code(pr);
418 :
419 9807 : return true;
420 : }
421 :
422 :
423 : /* patcher_invokeinterface *****************************************************
424 :
425 : Machine code:
426 :
427 : <patched call position>
428 : 4c 8b 17 mov (%rdi),%r10
429 : 4d 8b 92 00 00 00 00 mov 0x0(%r10),%r10
430 : 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
431 : 48 ff d0 callq *%rax
432 :
433 : *******************************************************************************/
434 :
435 624 : bool patcher_invokeinterface(patchref_t *pr)
436 : {
437 624 : uint8_t* pc = (uint8_t*) pr->mpc;
438 624 : unresolved_method* um = (unresolved_method*) pr->ref;
439 :
440 : // Resolve the method.
441 624 : methodinfo* m = resolve_method_eager(um);
442 :
443 624 : if (m == NULL)
444 0 : return false;
445 :
446 624 : pc += PATCHER_CALL_SIZE;
447 624 : pc += PATCH_ALIGNMENT((uintptr_t) pc, 6, sizeof(int32_t));
448 :
449 : // Patch interfacetable index.
450 624 : patch_checked_location((int32_t*) (pc + 6), (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - sizeof(methodptr) * m->clazz->index));
451 :
452 624 : int disp = PATCH_ALIGNMENT((uintptr_t) (pc + 3 + 7), 3, sizeof(int32_t));
453 624 : pc += disp;
454 : // Patch method offset.
455 624 : int32_t *loc = patch_checked_location((int32_t*) (pc + 3 + 7 + 3), (int32_t) (sizeof(methodptr) * (m - m->clazz->methods)));
456 :
457 : // Synchronize instruction cache.
458 624 : checked_icache_flush(pc + 6, SIZEOF_VOID_P + 3 + SIZEOF_VOID_P + disp, loc);
459 :
460 : // Patch back the original code.
461 624 : patcher_patch_code(pr);
462 :
463 624 : return true;
464 : }
465 :
466 :
467 : /* patcher_checkcast_interface *************************************************
468 :
469 : Machine code:
470 :
471 : <patched call position>
472 : 45 8b 9a 1c 00 00 00 mov 0x1c(%r10),%r11d
473 : 41 81 fb 00 00 00 00 cmp $0x0,%r11d
474 : 0f 8f 08 00 00 00 jg 0x00002aaaaae511d5
475 : 48 8b 0c 25 03 00 00 00 mov 0x3,%rcx
476 : 4d 8b 9a 00 00 00 00 mov 0x0(%r10),%r11
477 :
478 : *******************************************************************************/
479 :
480 13 : bool patcher_checkcast_interface(patchref_t *pr)
481 : {
482 13 : uint8_t* pc = (uint8_t*) pr->mpc;
483 13 : constant_classref* cr = (constant_classref*) pr->ref;
484 :
485 : // Resolve the class.
486 13 : classinfo* c = resolve_classref_eager(cr);
487 :
488 13 : if (c == NULL)
489 0 : return false;
490 :
491 13 : pc += PATCHER_CALL_SIZE;
492 13 : pc += PATCH_ALIGNMENT((uintptr_t) pc, 10, sizeof(int32_t));
493 :
494 : // Patch super class index.
495 13 : patch_checked_location((int32_t*) (pc + 10), c->index);
496 :
497 13 : int disp = PATCH_ALIGNMENT((uintptr_t) (pc + 7 + 7 + 6 + 8), 3, sizeof(int32_t));
498 13 : pc += disp;
499 13 : int32_t *loc = patch_checked_location((int32_t*) (pc + 7 + 7 + 6 + 8 + 3), (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - c->index * sizeof(methodptr*)));
500 :
501 : // Synchronize instruction cache.
502 13 : checked_icache_flush(pc + 10, sizeof(int32_t) + 6 + 8 + 3 + sizeof(int32_t) + disp, loc);
503 :
504 : // Patch back the original code.
505 13 : patcher_patch_code(pr);
506 :
507 13 : return true;
508 : }
509 :
510 :
511 : /* patcher_instanceof_interface ************************************************
512 :
513 : Machine code:
514 :
515 : <patched call position>
516 : 45 8b 9a 1c 00 00 00 mov 0x1c(%r10),%r11d
517 : 41 81 fb 00 00 00 00 cmp $0x0,%r11d
518 : 0f 8e 94 04 00 00 jle 0x00002aaaaab018f8
519 : 4d 8b 9a 00 00 00 00 mov 0x0(%r10),%r11
520 :
521 : *******************************************************************************/
522 :
523 30 : bool patcher_instanceof_interface(patchref_t *pr)
524 : {
525 30 : uint8_t* pc = (uint8_t*) pr->mpc;
526 30 : constant_classref* cr = (constant_classref*) pr->ref;
527 :
528 : // Resolve the class.
529 30 : classinfo* c = resolve_classref_eager(cr);
530 :
531 30 : if (c == NULL)
532 0 : return false;
533 :
534 30 : pc += PATCHER_CALL_SIZE;
535 30 : pc += PATCH_ALIGNMENT((uintptr_t) pc, 10, sizeof(int32_t));
536 :
537 : // Patch super class index.
538 30 : patch_checked_location((int32_t*) (pc + 10), c->index);
539 :
540 30 : int disp = PATCH_ALIGNMENT((uintptr_t) (pc + 7 + 7 + 6), 3, sizeof(int32_t));
541 30 : pc += disp;
542 30 : int32_t *loc = patch_checked_location((int32_t*) (pc + 7 + 7 + 6 + 3), (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - c->index * sizeof(methodptr*)));
543 :
544 : // Synchronize instruction cache.
545 30 : checked_icache_flush(pc + 10, sizeof(int32_t) + 6 + 3 + sizeof(int32_t) + disp, loc);
546 :
547 : // Patch back the original code.
548 30 : patcher_patch_code(pr);
549 :
550 30 : return true;
551 : }
552 :
553 :
554 : /*
555 : * These are local overrides for various environment variables in Emacs.
556 : * Please do not remove this and leave it at the end of the file, where
557 : * Emacs will automagically detect them.
558 : * ---------------------------------------------------------------------
559 : * Local variables:
560 : * mode: c++
561 : * indent-tabs-mode: t
562 : * c-basic-offset: 4
563 : * tab-width: 4
564 : * End:
565 : * vim:noexpandtab:sw=4:ts=4:
566 : */
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