root / exec-i386.c @ e026db58
History | View | Annotate | Download (13.7 kB)
1 |
/*
|
---|---|
2 |
* i386 emulator main execution loop
|
3 |
*
|
4 |
* Copyright (c) 2003 Fabrice Bellard
|
5 |
*
|
6 |
* This library is free software; you can redistribute it and/or
|
7 |
* modify it under the terms of the GNU Lesser General Public
|
8 |
* License as published by the Free Software Foundation; either
|
9 |
* version 2 of the License, or (at your option) any later version.
|
10 |
*
|
11 |
* This library is distributed in the hope that it will be useful,
|
12 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
* Lesser General Public License for more details.
|
15 |
*
|
16 |
* You should have received a copy of the GNU Lesser General Public
|
17 |
* License along with this library; if not, write to the Free Software
|
18 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
19 |
*/
|
20 |
#include "exec-i386.h" |
21 |
#include "disas.h" |
22 |
|
23 |
//#define DEBUG_EXEC
|
24 |
#define DEBUG_FLUSH
|
25 |
//#define DEBUG_SIGNAL
|
26 |
|
27 |
/* main execution loop */
|
28 |
|
29 |
/* maximum total translate dcode allocated */
|
30 |
#define CODE_GEN_BUFFER_SIZE (2048 * 1024) |
31 |
//#define CODE_GEN_BUFFER_SIZE (128 * 1024)
|
32 |
#define CODE_GEN_MAX_SIZE 65536 |
33 |
#define CODE_GEN_ALIGN 16 /* must be >= of the size of a icache line */ |
34 |
|
35 |
/* threshold to flush the translated code buffer */
|
36 |
#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
|
37 |
|
38 |
#define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64) |
39 |
#define CODE_GEN_HASH_BITS 15 |
40 |
#define CODE_GEN_HASH_SIZE (1 << CODE_GEN_HASH_BITS) |
41 |
|
42 |
typedef struct TranslationBlock { |
43 |
unsigned long pc; /* simulated PC corresponding to this block (EIP + CS base) */ |
44 |
unsigned long cs_base; /* CS base for this block */ |
45 |
unsigned int flags; /* flags defining in which context the code was generated */ |
46 |
uint8_t *tc_ptr; /* pointer to the translated code */
|
47 |
struct TranslationBlock *hash_next; /* next matching block */ |
48 |
} TranslationBlock; |
49 |
|
50 |
TranslationBlock tbs[CODE_GEN_MAX_BLOCKS]; |
51 |
TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE]; |
52 |
int nb_tbs;
|
53 |
|
54 |
uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE]; |
55 |
uint8_t *code_gen_ptr; |
56 |
|
57 |
/* thread support */
|
58 |
|
59 |
#ifdef __powerpc__
|
60 |
static inline int testandset (int *p) |
61 |
{ |
62 |
int ret;
|
63 |
__asm__ __volatile__ ( |
64 |
"0: lwarx %0,0,%1 ;"
|
65 |
" xor. %0,%3,%0;"
|
66 |
" bne 1f;"
|
67 |
" stwcx. %2,0,%1;"
|
68 |
" bne- 0b;"
|
69 |
"1: "
|
70 |
: "=&r" (ret)
|
71 |
: "r" (p), "r" (1), "r" (0) |
72 |
: "cr0", "memory"); |
73 |
return ret;
|
74 |
} |
75 |
#endif
|
76 |
|
77 |
#ifdef __i386__
|
78 |
static inline int testandset (int *p) |
79 |
{ |
80 |
char ret;
|
81 |
long int readval; |
82 |
|
83 |
__asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
|
84 |
: "=q" (ret), "=m" (*p), "=a" (readval) |
85 |
: "r" (1), "m" (*p), "a" (0) |
86 |
: "memory");
|
87 |
return ret;
|
88 |
} |
89 |
#endif
|
90 |
|
91 |
#ifdef __s390__
|
92 |
static inline int testandset (int *p) |
93 |
{ |
94 |
int ret;
|
95 |
|
96 |
__asm__ __volatile__ ("0: cs %0,%1,0(%2)\n"
|
97 |
" jl 0b"
|
98 |
: "=&d" (ret)
|
99 |
: "r" (1), "a" (p), "0" (*p) |
100 |
: "cc", "memory" ); |
101 |
return ret;
|
102 |
} |
103 |
#endif
|
104 |
|
105 |
#ifdef __alpha__
|
106 |
int testandset (int *p) |
107 |
{ |
108 |
int ret;
|
109 |
unsigned long one; |
110 |
|
111 |
__asm__ __volatile__ ("0: mov 1,%2\n"
|
112 |
" ldl_l %0,%1\n"
|
113 |
" stl_c %2,%1\n"
|
114 |
" beq %2,1f\n"
|
115 |
".subsection 2\n"
|
116 |
"1: br 0b\n"
|
117 |
".previous"
|
118 |
: "=r" (ret), "=m" (*p), "=r" (one) |
119 |
: "m" (*p));
|
120 |
return ret;
|
121 |
} |
122 |
#endif
|
123 |
|
124 |
int global_cpu_lock = 0; |
125 |
|
126 |
void cpu_lock(void) |
127 |
{ |
128 |
while (testandset(&global_cpu_lock));
|
129 |
} |
130 |
|
131 |
void cpu_unlock(void) |
132 |
{ |
133 |
global_cpu_lock = 0;
|
134 |
} |
135 |
|
136 |
/* exception support */
|
137 |
/* NOTE: not static to force relocation generation by GCC */
|
138 |
void raise_exception(int exception_index) |
139 |
{ |
140 |
/* NOTE: the register at this point must be saved by hand because
|
141 |
longjmp restore them */
|
142 |
#ifdef reg_EAX
|
143 |
env->regs[R_EAX] = EAX; |
144 |
#endif
|
145 |
#ifdef reg_ECX
|
146 |
env->regs[R_ECX] = ECX; |
147 |
#endif
|
148 |
#ifdef reg_EDX
|
149 |
env->regs[R_EDX] = EDX; |
150 |
#endif
|
151 |
#ifdef reg_EBX
|
152 |
env->regs[R_EBX] = EBX; |
153 |
#endif
|
154 |
#ifdef reg_ESP
|
155 |
env->regs[R_ESP] = ESP; |
156 |
#endif
|
157 |
#ifdef reg_EBP
|
158 |
env->regs[R_EBP] = EBP; |
159 |
#endif
|
160 |
#ifdef reg_ESI
|
161 |
env->regs[R_ESI] = ESI; |
162 |
#endif
|
163 |
#ifdef reg_EDI
|
164 |
env->regs[R_EDI] = EDI; |
165 |
#endif
|
166 |
env->exception_index = exception_index; |
167 |
longjmp(env->jmp_env, 1);
|
168 |
} |
169 |
|
170 |
#if defined(DEBUG_EXEC)
|
171 |
static const char *cc_op_str[] = { |
172 |
"DYNAMIC",
|
173 |
"EFLAGS",
|
174 |
"MUL",
|
175 |
"ADDB",
|
176 |
"ADDW",
|
177 |
"ADDL",
|
178 |
"ADCB",
|
179 |
"ADCW",
|
180 |
"ADCL",
|
181 |
"SUBB",
|
182 |
"SUBW",
|
183 |
"SUBL",
|
184 |
"SBBB",
|
185 |
"SBBW",
|
186 |
"SBBL",
|
187 |
"LOGICB",
|
188 |
"LOGICW",
|
189 |
"LOGICL",
|
190 |
"INCB",
|
191 |
"INCW",
|
192 |
"INCL",
|
193 |
"DECB",
|
194 |
"DECW",
|
195 |
"DECL",
|
196 |
"SHLB",
|
197 |
"SHLW",
|
198 |
"SHLL",
|
199 |
"SARB",
|
200 |
"SARW",
|
201 |
"SARL",
|
202 |
}; |
203 |
|
204 |
static void cpu_x86_dump_state(FILE *f) |
205 |
{ |
206 |
int eflags;
|
207 |
eflags = cc_table[CC_OP].compute_all(); |
208 |
eflags |= (DF & DF_MASK); |
209 |
fprintf(f, |
210 |
"EAX=%08x EBX=%08X ECX=%08x EDX=%08x\n"
|
211 |
"ESI=%08x EDI=%08X EBP=%08x ESP=%08x\n"
|
212 |
"CCS=%08x CCD=%08x CCO=%-8s EFL=%c%c%c%c%c%c%c\n"
|
213 |
"EIP=%08x\n",
|
214 |
env->regs[R_EAX], env->regs[R_EBX], env->regs[R_ECX], env->regs[R_EDX], |
215 |
env->regs[R_ESI], env->regs[R_EDI], env->regs[R_EBP], env->regs[R_ESP], |
216 |
env->cc_src, env->cc_dst, cc_op_str[env->cc_op], |
217 |
eflags & DF_MASK ? 'D' : '-', |
218 |
eflags & CC_O ? 'O' : '-', |
219 |
eflags & CC_S ? 'S' : '-', |
220 |
eflags & CC_Z ? 'Z' : '-', |
221 |
eflags & CC_A ? 'A' : '-', |
222 |
eflags & CC_P ? 'P' : '-', |
223 |
eflags & CC_C ? 'C' : '-', |
224 |
env->eip); |
225 |
#if 1 |
226 |
fprintf(f, "ST0=%f ST1=%f ST2=%f ST3=%f\n",
|
227 |
(double)ST0, (double)ST1, (double)ST(2), (double)ST(3)); |
228 |
#endif
|
229 |
} |
230 |
|
231 |
#endif
|
232 |
|
233 |
void cpu_x86_tblocks_init(void) |
234 |
{ |
235 |
if (!code_gen_ptr) {
|
236 |
code_gen_ptr = code_gen_buffer; |
237 |
} |
238 |
} |
239 |
|
240 |
/* flush all the translation blocks */
|
241 |
static void tb_flush(void) |
242 |
{ |
243 |
int i;
|
244 |
#ifdef DEBUG_FLUSH
|
245 |
printf("gemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
|
246 |
code_gen_ptr - code_gen_buffer, |
247 |
nb_tbs, |
248 |
(code_gen_ptr - code_gen_buffer) / nb_tbs); |
249 |
#endif
|
250 |
nb_tbs = 0;
|
251 |
for(i = 0;i < CODE_GEN_HASH_SIZE; i++) |
252 |
tb_hash[i] = NULL;
|
253 |
code_gen_ptr = code_gen_buffer; |
254 |
/* XXX: flush processor icache at this point */
|
255 |
} |
256 |
|
257 |
/* find a translation block in the translation cache. If not found,
|
258 |
return NULL and the pointer to the last element of the list in pptb */
|
259 |
static inline TranslationBlock *tb_find(TranslationBlock ***pptb, |
260 |
unsigned long pc, |
261 |
unsigned long cs_base, |
262 |
unsigned int flags) |
263 |
{ |
264 |
TranslationBlock **ptb, *tb; |
265 |
unsigned int h; |
266 |
|
267 |
h = pc & (CODE_GEN_HASH_SIZE - 1);
|
268 |
ptb = &tb_hash[h]; |
269 |
for(;;) {
|
270 |
tb = *ptb; |
271 |
if (!tb)
|
272 |
break;
|
273 |
if (tb->pc == pc && tb->cs_base == cs_base && tb->flags == flags)
|
274 |
return tb;
|
275 |
ptb = &tb->hash_next; |
276 |
} |
277 |
*pptb = ptb; |
278 |
return NULL; |
279 |
} |
280 |
|
281 |
/* allocate a new translation block. flush the translation buffer if
|
282 |
too many translation blocks or too much generated code */
|
283 |
static inline TranslationBlock *tb_alloc(void) |
284 |
{ |
285 |
TranslationBlock *tb; |
286 |
if (nb_tbs >= CODE_GEN_MAX_BLOCKS ||
|
287 |
(code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE) |
288 |
tb_flush(); |
289 |
tb = &tbs[nb_tbs++]; |
290 |
return tb;
|
291 |
} |
292 |
|
293 |
int cpu_x86_exec(CPUX86State *env1)
|
294 |
{ |
295 |
int saved_T0, saved_T1, saved_A0;
|
296 |
CPUX86State *saved_env; |
297 |
#ifdef reg_EAX
|
298 |
int saved_EAX;
|
299 |
#endif
|
300 |
#ifdef reg_ECX
|
301 |
int saved_ECX;
|
302 |
#endif
|
303 |
#ifdef reg_EDX
|
304 |
int saved_EDX;
|
305 |
#endif
|
306 |
#ifdef reg_EBX
|
307 |
int saved_EBX;
|
308 |
#endif
|
309 |
#ifdef reg_ESP
|
310 |
int saved_ESP;
|
311 |
#endif
|
312 |
#ifdef reg_EBP
|
313 |
int saved_EBP;
|
314 |
#endif
|
315 |
#ifdef reg_ESI
|
316 |
int saved_ESI;
|
317 |
#endif
|
318 |
#ifdef reg_EDI
|
319 |
int saved_EDI;
|
320 |
#endif
|
321 |
int code_gen_size, ret;
|
322 |
void (*gen_func)(void); |
323 |
TranslationBlock *tb, **ptb; |
324 |
uint8_t *tc_ptr, *cs_base, *pc; |
325 |
unsigned int flags; |
326 |
|
327 |
/* first we save global registers */
|
328 |
saved_T0 = T0; |
329 |
saved_T1 = T1; |
330 |
saved_A0 = A0; |
331 |
saved_env = env; |
332 |
env = env1; |
333 |
#ifdef reg_EAX
|
334 |
saved_EAX = EAX; |
335 |
EAX = env->regs[R_EAX]; |
336 |
#endif
|
337 |
#ifdef reg_ECX
|
338 |
saved_ECX = ECX; |
339 |
ECX = env->regs[R_ECX]; |
340 |
#endif
|
341 |
#ifdef reg_EDX
|
342 |
saved_EDX = EDX; |
343 |
EDX = env->regs[R_EDX]; |
344 |
#endif
|
345 |
#ifdef reg_EBX
|
346 |
saved_EBX = EBX; |
347 |
EBX = env->regs[R_EBX]; |
348 |
#endif
|
349 |
#ifdef reg_ESP
|
350 |
saved_ESP = ESP; |
351 |
ESP = env->regs[R_ESP]; |
352 |
#endif
|
353 |
#ifdef reg_EBP
|
354 |
saved_EBP = EBP; |
355 |
EBP = env->regs[R_EBP]; |
356 |
#endif
|
357 |
#ifdef reg_ESI
|
358 |
saved_ESI = ESI; |
359 |
ESI = env->regs[R_ESI]; |
360 |
#endif
|
361 |
#ifdef reg_EDI
|
362 |
saved_EDI = EDI; |
363 |
EDI = env->regs[R_EDI]; |
364 |
#endif
|
365 |
|
366 |
/* put eflags in CPU temporary format */
|
367 |
CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); |
368 |
DF = 1 - (2 * ((env->eflags >> 10) & 1)); |
369 |
CC_OP = CC_OP_EFLAGS; |
370 |
env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C); |
371 |
env->interrupt_request = 0;
|
372 |
|
373 |
/* prepare setjmp context for exception handling */
|
374 |
if (setjmp(env->jmp_env) == 0) { |
375 |
for(;;) {
|
376 |
if (env->interrupt_request) {
|
377 |
raise_exception(EXCP_INTERRUPT); |
378 |
} |
379 |
#ifdef DEBUG_EXEC
|
380 |
if (loglevel) {
|
381 |
cpu_x86_dump_state(logfile); |
382 |
} |
383 |
#endif
|
384 |
/* we compute the CPU state. We assume it will not
|
385 |
change during the whole generated block. */
|
386 |
flags = env->seg_cache[R_CS].seg_32bit << GEN_FLAG_CODE32_SHIFT; |
387 |
flags |= env->seg_cache[R_SS].seg_32bit << GEN_FLAG_SS32_SHIFT; |
388 |
flags |= (((unsigned long)env->seg_cache[R_DS].base | |
389 |
(unsigned long)env->seg_cache[R_ES].base | |
390 |
(unsigned long)env->seg_cache[R_SS].base) != 0) << |
391 |
GEN_FLAG_ADDSEG_SHIFT; |
392 |
flags |= (env->eflags & VM_MASK) >> (17 - GEN_FLAG_VM_SHIFT);
|
393 |
cs_base = env->seg_cache[R_CS].base; |
394 |
pc = cs_base + env->eip; |
395 |
tb = tb_find(&ptb, (unsigned long)pc, (unsigned long)cs_base, |
396 |
flags); |
397 |
if (!tb) {
|
398 |
/* if no translated code available, then translate it now */
|
399 |
/* XXX: very inefficient: we lock all the cpus when
|
400 |
generating code */
|
401 |
cpu_lock(); |
402 |
tc_ptr = code_gen_ptr; |
403 |
ret = cpu_x86_gen_code(code_gen_ptr, CODE_GEN_MAX_SIZE, |
404 |
&code_gen_size, pc, cs_base, flags); |
405 |
/* if invalid instruction, signal it */
|
406 |
if (ret != 0) { |
407 |
cpu_unlock(); |
408 |
raise_exception(EXCP06_ILLOP); |
409 |
} |
410 |
tb = tb_alloc(); |
411 |
*ptb = tb; |
412 |
tb->pc = (unsigned long)pc; |
413 |
tb->cs_base = (unsigned long)cs_base; |
414 |
tb->flags = flags; |
415 |
tb->tc_ptr = tc_ptr; |
416 |
tb->hash_next = NULL;
|
417 |
code_gen_ptr = (void *)(((unsigned long)code_gen_ptr + code_gen_size + CODE_GEN_ALIGN - 1) & ~(CODE_GEN_ALIGN - 1)); |
418 |
cpu_unlock(); |
419 |
} |
420 |
if (loglevel) {
|
421 |
fprintf(logfile, "Trace 0x%08lx [0x%08lx] %s\n",
|
422 |
(long)tb->tc_ptr, (long)tb->pc, |
423 |
lookup_symbol((void *)tb->pc));
|
424 |
fflush(logfile); |
425 |
} |
426 |
/* execute the generated code */
|
427 |
tc_ptr = tb->tc_ptr; |
428 |
gen_func = (void *)tc_ptr;
|
429 |
gen_func(); |
430 |
} |
431 |
} |
432 |
ret = env->exception_index; |
433 |
|
434 |
/* restore flags in standard format */
|
435 |
env->eflags = env->eflags | cc_table[CC_OP].compute_all() | (DF & DF_MASK); |
436 |
|
437 |
/* restore global registers */
|
438 |
#ifdef reg_EAX
|
439 |
EAX = saved_EAX; |
440 |
#endif
|
441 |
#ifdef reg_ECX
|
442 |
ECX = saved_ECX; |
443 |
#endif
|
444 |
#ifdef reg_EDX
|
445 |
EDX = saved_EDX; |
446 |
#endif
|
447 |
#ifdef reg_EBX
|
448 |
EBX = saved_EBX; |
449 |
#endif
|
450 |
#ifdef reg_ESP
|
451 |
ESP = saved_ESP; |
452 |
#endif
|
453 |
#ifdef reg_EBP
|
454 |
EBP = saved_EBP; |
455 |
#endif
|
456 |
#ifdef reg_ESI
|
457 |
ESI = saved_ESI; |
458 |
#endif
|
459 |
#ifdef reg_EDI
|
460 |
EDI = saved_EDI; |
461 |
#endif
|
462 |
T0 = saved_T0; |
463 |
T1 = saved_T1; |
464 |
A0 = saved_A0; |
465 |
env = saved_env; |
466 |
return ret;
|
467 |
} |
468 |
|
469 |
void cpu_x86_interrupt(CPUX86State *s)
|
470 |
{ |
471 |
s->interrupt_request = 1;
|
472 |
} |
473 |
|
474 |
|
475 |
void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector) |
476 |
{ |
477 |
CPUX86State *saved_env; |
478 |
|
479 |
saved_env = env; |
480 |
env = s; |
481 |
load_seg(seg_reg, selector); |
482 |
env = saved_env; |
483 |
} |
484 |
|
485 |
#undef EAX
|
486 |
#undef ECX
|
487 |
#undef EDX
|
488 |
#undef EBX
|
489 |
#undef ESP
|
490 |
#undef EBP
|
491 |
#undef ESI
|
492 |
#undef EDI
|
493 |
#undef EIP
|
494 |
#include <signal.h> |
495 |
#include <sys/ucontext.h> |
496 |
|
497 |
static inline int handle_cpu_signal(unsigned long pc, |
498 |
sigset_t *old_set) |
499 |
{ |
500 |
#ifdef DEBUG_SIGNAL
|
501 |
printf("gemu: SIGSEGV pc=0x%08lx oldset=0x%08lx\n",
|
502 |
pc, *(unsigned long *)old_set); |
503 |
#endif
|
504 |
if (pc >= (unsigned long)code_gen_buffer && |
505 |
pc < (unsigned long)code_gen_buffer + CODE_GEN_BUFFER_SIZE) { |
506 |
/* the PC is inside the translated code. It means that we have
|
507 |
a virtual CPU fault */
|
508 |
/* we restore the process signal mask as the sigreturn should
|
509 |
do it */
|
510 |
sigprocmask(SIG_SETMASK, old_set, NULL);
|
511 |
/* XXX: need to compute virtual pc position by retranslating
|
512 |
code. The rest of the CPU state should be correct. */
|
513 |
raise_exception(EXCP0D_GPF); |
514 |
/* never comes here */
|
515 |
return 1; |
516 |
} else {
|
517 |
return 0; |
518 |
} |
519 |
} |
520 |
|
521 |
int cpu_x86_signal_handler(int host_signum, struct siginfo *info, |
522 |
void *puc)
|
523 |
{ |
524 |
#if defined(__i386__)
|
525 |
struct ucontext *uc = puc;
|
526 |
unsigned long pc; |
527 |
sigset_t *pold_set; |
528 |
|
529 |
#ifndef REG_EIP
|
530 |
/* for glibc 2.1 */
|
531 |
#define REG_EIP EIP
|
532 |
#endif
|
533 |
pc = uc->uc_mcontext.gregs[REG_EIP]; |
534 |
pold_set = &uc->uc_sigmask; |
535 |
return handle_cpu_signal(pc, pold_set);
|
536 |
#else
|
537 |
#warning No CPU specific signal handler: cannot handle target SIGSEGV events
|
538 |
return 0; |
539 |
#endif
|
540 |
} |