1 /* 2 * Emulation of Linux signals 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program 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 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 #include <stdlib.h> 21 #include <stdio.h> 22 #include <string.h> 23 #include <stdarg.h> 24 #include <unistd.h> 25 #include <signal.h> 26 #include <errno.h> 27 #include <sys/ucontext.h> 28 29 #ifdef __ia64__ 30 #undef uc_mcontext 31 #undef uc_sigmask 32 #undef uc_stack 33 #undef uc_link 34 #endif 35 36 #include "qemu.h" 37 38 //#define DEBUG_SIGNAL 39 40 #define MAX_SIGQUEUE_SIZE 1024 41 42 struct sigqueue { 43 struct sigqueue *next; 44 target_siginfo_t info; 45 }; 46 47 struct emulated_sigaction { 48 struct target_sigaction sa; 49 int pending; /* true if signal is pending */ 50 struct sigqueue *first; 51 struct sigqueue info; /* in order to always have memory for the 52 first signal, we put it here */ 53 }; 54 55 static struct emulated_sigaction sigact_table[TARGET_NSIG]; 56 static struct sigqueue sigqueue_table[MAX_SIGQUEUE_SIZE]; /* siginfo queue */ 57 static struct sigqueue *first_free; /* first free siginfo queue entry */ 58 static int signal_pending; /* non zero if a signal may be pending */ 59 60 static void host_signal_handler(int host_signum, siginfo_t *info, 61 void *puc); 62 63 /* XXX: do it properly */ 64 static inline int host_to_target_signal(int sig) 65 { 66 return sig; 67 } 68 69 static inline int target_to_host_signal(int sig) 70 { 71 return sig; 72 } 73 74 void host_to_target_sigset(target_sigset_t *d, sigset_t *s) 75 { 76 int i; 77 for(i = 0;i < TARGET_NSIG_WORDS; i++) { 78 d->sig[i] = tswapl(((unsigned long *)s)[i]); 79 } 80 } 81 82 void target_to_host_sigset(sigset_t *d, target_sigset_t *s) 83 { 84 int i; 85 for(i = 0;i < TARGET_NSIG_WORDS; i++) { 86 ((unsigned long *)d)[i] = tswapl(s->sig[i]); 87 } 88 } 89 90 void host_to_target_old_sigset(target_ulong *old_sigset, 91 const sigset_t *sigset) 92 { 93 *old_sigset = tswap32(*(unsigned long *)sigset & 0xffffffff); 94 } 95 96 void target_to_host_old_sigset(sigset_t *sigset, 97 const target_ulong *old_sigset) 98 { 99 sigemptyset(sigset); 100 *(unsigned long *)sigset = tswapl(*old_sigset); 101 } 102 103 /* siginfo conversion */ 104 105 static inline void host_to_target_siginfo_noswap(target_siginfo_t *tinfo, 106 const siginfo_t *info) 107 { 108 int sig; 109 sig = host_to_target_signal(info->si_signo); 110 tinfo->si_signo = sig; 111 tinfo->si_errno = 0; 112 tinfo->si_code = 0; 113 if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || 114 sig == SIGBUS || sig == SIGTRAP) { 115 /* should never come here, but who knows. The information for 116 the target is irrelevant */ 117 tinfo->_sifields._sigfault._addr = 0; 118 } else if (sig >= TARGET_SIGRTMIN) { 119 tinfo->_sifields._rt._pid = info->si_pid; 120 tinfo->_sifields._rt._uid = info->si_uid; 121 /* XXX: potential problem if 64 bit */ 122 tinfo->_sifields._rt._sigval.sival_ptr = 123 (target_ulong)info->si_value.sival_ptr; 124 } 125 } 126 127 static void tswap_siginfo(target_siginfo_t *tinfo, 128 const target_siginfo_t *info) 129 { 130 int sig; 131 sig = info->si_signo; 132 tinfo->si_signo = tswap32(sig); 133 tinfo->si_errno = tswap32(info->si_errno); 134 tinfo->si_code = tswap32(info->si_code); 135 if (sig == SIGILL || sig == SIGFPE || sig == SIGSEGV || 136 sig == SIGBUS || sig == SIGTRAP) { 137 tinfo->_sifields._sigfault._addr = 138 tswapl(info->_sifields._sigfault._addr); 139 } else if (sig >= TARGET_SIGRTMIN) { 140 tinfo->_sifields._rt._pid = tswap32(info->_sifields._rt._pid); 141 tinfo->_sifields._rt._uid = tswap32(info->_sifields._rt._uid); 142 tinfo->_sifields._rt._sigval.sival_ptr = 143 tswapl(info->_sifields._rt._sigval.sival_ptr); 144 } 145 } 146 147 148 void host_to_target_siginfo(target_siginfo_t *tinfo, const siginfo_t *info) 149 { 150 host_to_target_siginfo_noswap(tinfo, info); 151 tswap_siginfo(tinfo, tinfo); 152 } 153 154 /* XXX: we support only POSIX RT signals are used. */ 155 /* XXX: find a solution for 64 bit (additionnal malloced data is needed) */ 156 void target_to_host_siginfo(siginfo_t *info, const target_siginfo_t *tinfo) 157 { 158 info->si_signo = tswap32(tinfo->si_signo); 159 info->si_errno = tswap32(tinfo->si_errno); 160 info->si_code = tswap32(tinfo->si_code); 161 info->si_pid = tswap32(tinfo->_sifields._rt._pid); 162 info->si_uid = tswap32(tinfo->_sifields._rt._uid); 163 info->si_value.sival_ptr = 164 (void *)tswapl(tinfo->_sifields._rt._sigval.sival_ptr); 165 } 166 167 void signal_init(void) 168 { 169 struct sigaction act; 170 int i; 171 172 /* set all host signal handlers. ALL signals are blocked during 173 the handlers to serialize them. */ 174 sigfillset(&act.sa_mask); 175 act.sa_flags = SA_SIGINFO; 176 act.sa_sigaction = host_signal_handler; 177 for(i = 1; i < NSIG; i++) { 178 sigaction(i, &act, NULL); 179 } 180 181 memset(sigact_table, 0, sizeof(sigact_table)); 182 183 first_free = &sigqueue_table[0]; 184 for(i = 0; i < MAX_SIGQUEUE_SIZE - 1; i++) 185 sigqueue_table[i].next = &sigqueue_table[i + 1]; 186 sigqueue_table[MAX_SIGQUEUE_SIZE - 1].next = NULL; 187 } 188 189 /* signal queue handling */ 190 191 static inline struct sigqueue *alloc_sigqueue(void) 192 { 193 struct sigqueue *q = first_free; 194 if (!q) 195 return NULL; 196 first_free = q->next; 197 return q; 198 } 199 200 static inline void free_sigqueue(struct sigqueue *q) 201 { 202 q->next = first_free; 203 first_free = q; 204 } 205 206 /* abort execution with signal */ 207 void __attribute((noreturn)) force_sig(int sig) 208 { 209 int host_sig; 210 host_sig = target_to_host_signal(sig); 211 fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n", 212 sig, strsignal(host_sig)); 213 #if 1 214 _exit(-host_sig); 215 #else 216 { 217 struct sigaction act; 218 sigemptyset(&act.sa_mask); 219 act.sa_flags = SA_SIGINFO; 220 act.sa_sigaction = SIG_DFL; 221 sigaction(SIGABRT, &act, NULL); 222 abort(); 223 } 224 #endif 225 } 226 227 /* queue a signal so that it will be send to the virtual CPU as soon 228 as possible */ 229 int queue_signal(int sig, target_siginfo_t *info) 230 { 231 struct emulated_sigaction *k; 232 struct sigqueue *q, **pq; 233 target_ulong handler; 234 235 #if defined(DEBUG_SIGNAL) 236 fprintf(stderr, "queue_signal: sig=%d\n", 237 sig); 238 #endif 239 k = &sigact_table[sig - 1]; 240 handler = k->sa._sa_handler; 241 if (handler == TARGET_SIG_DFL) { 242 /* default handler : ignore some signal. The other are fatal */ 243 if (sig != TARGET_SIGCHLD && 244 sig != TARGET_SIGURG && 245 sig != TARGET_SIGWINCH) { 246 force_sig(sig); 247 } else { 248 return 0; /* indicate ignored */ 249 } 250 } else if (handler == TARGET_SIG_IGN) { 251 /* ignore signal */ 252 return 0; 253 } else if (handler == TARGET_SIG_ERR) { 254 force_sig(sig); 255 } else { 256 pq = &k->first; 257 if (sig < TARGET_SIGRTMIN) { 258 /* if non real time signal, we queue exactly one signal */ 259 if (!k->pending) 260 q = &k->info; 261 else 262 return 0; 263 } else { 264 if (!k->pending) { 265 /* first signal */ 266 q = &k->info; 267 } else { 268 q = alloc_sigqueue(); 269 if (!q) 270 return -EAGAIN; 271 while (*pq != NULL) 272 pq = &(*pq)->next; 273 } 274 } 275 *pq = q; 276 q->info = *info; 277 q->next = NULL; 278 k->pending = 1; 279 /* signal that a new signal is pending */ 280 signal_pending = 1; 281 return 1; /* indicates that the signal was queued */ 282 } 283 } 284 285 #if defined(DEBUG_SIGNAL) 286 #ifdef __i386__ 287 static void dump_regs(struct ucontext *uc) 288 { 289 fprintf(stderr, 290 "EAX=%08x EBX=%08x ECX=%08x EDX=%08x\n" 291 "ESI=%08x EDI=%08x EBP=%08x ESP=%08x\n" 292 "EFL=%08x EIP=%08x\n", 293 uc->uc_mcontext.gregs[EAX], 294 uc->uc_mcontext.gregs[EBX], 295 uc->uc_mcontext.gregs[ECX], 296 uc->uc_mcontext.gregs[EDX], 297 uc->uc_mcontext.gregs[ESI], 298 uc->uc_mcontext.gregs[EDI], 299 uc->uc_mcontext.gregs[EBP], 300 uc->uc_mcontext.gregs[ESP], 301 uc->uc_mcontext.gregs[EFL], 302 uc->uc_mcontext.gregs[EIP]); 303 } 304 #else 305 static void dump_regs(struct ucontext *uc) 306 { 307 } 308 #endif 309 310 #endif 311 312 static void host_signal_handler(int host_signum, siginfo_t *info, 313 void *puc) 314 { 315 int sig; 316 target_siginfo_t tinfo; 317 318 /* the CPU emulator uses some host signals to detect exceptions, 319 we we forward to it some signals */ 320 if (host_signum == SIGSEGV || host_signum == SIGBUS) { 321 if (cpu_x86_signal_handler(host_signum, info, puc)) 322 return; 323 } 324 325 /* get target signal number */ 326 sig = host_to_target_signal(host_signum); 327 if (sig < 1 || sig > TARGET_NSIG) 328 return; 329 #if defined(DEBUG_SIGNAL) 330 fprintf(stderr, "qemu: got signal %d\n", sig); 331 dump_regs(puc); 332 #endif 333 host_to_target_siginfo_noswap(&tinfo, info); 334 if (queue_signal(sig, &tinfo) == 1) { 335 /* interrupt the virtual CPU as soon as possible */ 336 cpu_x86_interrupt(global_env); 337 } 338 } 339 340 int do_sigaction(int sig, const struct target_sigaction *act, 341 struct target_sigaction *oact) 342 { 343 struct emulated_sigaction *k; 344 345 if (sig < 1 || sig > TARGET_NSIG) 346 return -EINVAL; 347 k = &sigact_table[sig - 1]; 348 #if defined(DEBUG_SIGNAL) && 0 349 fprintf(stderr, "sigaction sig=%d act=0x%08x, oact=0x%08x\n", 350 sig, (int)act, (int)oact); 351 #endif 352 if (oact) { 353 oact->_sa_handler = tswapl(k->sa._sa_handler); 354 oact->sa_flags = tswapl(k->sa.sa_flags); 355 oact->sa_restorer = tswapl(k->sa.sa_restorer); 356 oact->sa_mask = k->sa.sa_mask; 357 } 358 if (act) { 359 k->sa._sa_handler = tswapl(act->_sa_handler); 360 k->sa.sa_flags = tswapl(act->sa_flags); 361 k->sa.sa_restorer = tswapl(act->sa_restorer); 362 k->sa.sa_mask = act->sa_mask; 363 } 364 return 0; 365 } 366 367 #ifdef TARGET_I386 368 369 /* from the Linux kernel */ 370 371 struct target_fpreg { 372 uint16_t significand[4]; 373 uint16_t exponent; 374 }; 375 376 struct target_fpxreg { 377 uint16_t significand[4]; 378 uint16_t exponent; 379 uint16_t padding[3]; 380 }; 381 382 struct target_xmmreg { 383 target_ulong element[4]; 384 }; 385 386 struct target_fpstate { 387 /* Regular FPU environment */ 388 target_ulong cw; 389 target_ulong sw; 390 target_ulong tag; 391 target_ulong ipoff; 392 target_ulong cssel; 393 target_ulong dataoff; 394 target_ulong datasel; 395 struct target_fpreg _st[8]; 396 uint16_t status; 397 uint16_t magic; /* 0xffff = regular FPU data only */ 398 399 /* FXSR FPU environment */ 400 target_ulong _fxsr_env[6]; /* FXSR FPU env is ignored */ 401 target_ulong mxcsr; 402 target_ulong reserved; 403 struct target_fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */ 404 struct target_xmmreg _xmm[8]; 405 target_ulong padding[56]; 406 }; 407 408 #define X86_FXSR_MAGIC 0x0000 409 410 struct target_sigcontext { 411 uint16_t gs, __gsh; 412 uint16_t fs, __fsh; 413 uint16_t es, __esh; 414 uint16_t ds, __dsh; 415 target_ulong edi; 416 target_ulong esi; 417 target_ulong ebp; 418 target_ulong esp; 419 target_ulong ebx; 420 target_ulong edx; 421 target_ulong ecx; 422 target_ulong eax; 423 target_ulong trapno; 424 target_ulong err; 425 target_ulong eip; 426 uint16_t cs, __csh; 427 target_ulong eflags; 428 target_ulong esp_at_signal; 429 uint16_t ss, __ssh; 430 target_ulong fpstate; /* pointer */ 431 target_ulong oldmask; 432 target_ulong cr2; 433 }; 434 435 typedef struct target_sigaltstack { 436 target_ulong ss_sp; 437 int ss_flags; 438 target_ulong ss_size; 439 } target_stack_t; 440 441 struct target_ucontext { 442 target_ulong uc_flags; 443 target_ulong uc_link; 444 target_stack_t uc_stack; 445 struct target_sigcontext uc_mcontext; 446 target_sigset_t uc_sigmask; /* mask last for extensibility */ 447 }; 448 449 struct sigframe 450 { 451 target_ulong pretcode; 452 int sig; 453 struct target_sigcontext sc; 454 struct target_fpstate fpstate; 455 target_ulong extramask[TARGET_NSIG_WORDS-1]; 456 char retcode[8]; 457 }; 458 459 struct rt_sigframe 460 { 461 target_ulong pretcode; 462 int sig; 463 target_ulong pinfo; 464 target_ulong puc; 465 struct target_siginfo info; 466 struct target_ucontext uc; 467 struct target_fpstate fpstate; 468 char retcode[8]; 469 }; 470 471 /* 472 * Set up a signal frame. 473 */ 474 475 #define __put_user(x,ptr)\ 476 ({\ 477 int size = sizeof(*ptr);\ 478 switch(size) {\ 479 case 1:\ 480 stb(ptr, (typeof(*ptr))(x));\ 481 break;\ 482 case 2:\ 483 stw(ptr, (typeof(*ptr))(x));\ 484 break;\ 485 case 4:\ 486 stl(ptr, (typeof(*ptr))(x));\ 487 break;\ 488 case 8:\ 489 stq(ptr, (typeof(*ptr))(x));\ 490 break;\ 491 default:\ 492 abort();\ 493 }\ 494 0;\ 495 }) 496 497 #define get_user(val, ptr) (typeof(*ptr))(*(ptr)) 498 499 500 #define __copy_to_user(dst, src, size)\ 501 ({\ 502 memcpy(dst, src, size);\ 503 0;\ 504 }) 505 506 static inline int copy_siginfo_to_user(target_siginfo_t *tinfo, 507 const target_siginfo_t *info) 508 { 509 tswap_siginfo(tinfo, info); 510 return 0; 511 } 512 513 /* XXX: save x87 state */ 514 static int 515 setup_sigcontext(struct target_sigcontext *sc, struct target_fpstate *fpstate, 516 CPUX86State *env, unsigned long mask) 517 { 518 int err = 0; 519 520 err |= __put_user(env->segs[R_GS], (unsigned int *)&sc->gs); 521 err |= __put_user(env->segs[R_FS], (unsigned int *)&sc->fs); 522 err |= __put_user(env->segs[R_ES], (unsigned int *)&sc->es); 523 err |= __put_user(env->segs[R_DS], (unsigned int *)&sc->ds); 524 err |= __put_user(env->regs[R_EDI], &sc->edi); 525 err |= __put_user(env->regs[R_ESI], &sc->esi); 526 err |= __put_user(env->regs[R_EBP], &sc->ebp); 527 err |= __put_user(env->regs[R_ESP], &sc->esp); 528 err |= __put_user(env->regs[R_EBX], &sc->ebx); 529 err |= __put_user(env->regs[R_EDX], &sc->edx); 530 err |= __put_user(env->regs[R_ECX], &sc->ecx); 531 err |= __put_user(env->regs[R_EAX], &sc->eax); 532 err |= __put_user(env->exception_index, &sc->trapno); 533 err |= __put_user(env->error_code, &sc->err); 534 err |= __put_user(env->eip, &sc->eip); 535 err |= __put_user(env->segs[R_CS], (unsigned int *)&sc->cs); 536 err |= __put_user(env->eflags, &sc->eflags); 537 err |= __put_user(env->regs[R_ESP], &sc->esp_at_signal); 538 err |= __put_user(env->segs[R_SS], (unsigned int *)&sc->ss); 539 #if 0 540 tmp = save_i387(fpstate); 541 if (tmp < 0) 542 err = 1; 543 else 544 err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); 545 #else 546 err |= __put_user(0, &sc->fpstate); 547 #endif 548 /* non-iBCS2 extensions.. */ 549 err |= __put_user(mask, &sc->oldmask); 550 err |= __put_user(/*current->thread.cr2*/ 0, &sc->cr2); 551 return err; 552 } 553 554 /* 555 * Determine which stack to use.. 556 */ 557 558 static inline void * 559 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size) 560 { 561 unsigned long esp; 562 563 /* Default to using normal stack */ 564 esp = env->regs[R_ESP]; 565 #if 0 566 /* This is the X/Open sanctioned signal stack switching. */ 567 if (ka->sa.sa_flags & SA_ONSTACK) { 568 if (sas_ss_flags(esp) == 0) 569 esp = current->sas_ss_sp + current->sas_ss_size; 570 } 571 572 /* This is the legacy signal stack switching. */ 573 else if ((regs->xss & 0xffff) != __USER_DS && 574 !(ka->sa.sa_flags & SA_RESTORER) && 575 ka->sa.sa_restorer) { 576 esp = (unsigned long) ka->sa.sa_restorer; 577 } 578 #endif 579 return (void *)((esp - frame_size) & -8ul); 580 } 581 582 static void setup_frame(int sig, struct emulated_sigaction *ka, 583 target_sigset_t *set, CPUX86State *env) 584 { 585 struct sigframe *frame; 586 int err = 0; 587 588 frame = get_sigframe(ka, env, sizeof(*frame)); 589 590 #if 0 591 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 592 goto give_sigsegv; 593 #endif 594 err |= __put_user((/*current->exec_domain 595 && current->exec_domain->signal_invmap 596 && sig < 32 597 ? current->exec_domain->signal_invmap[sig] 598 : */ sig), 599 &frame->sig); 600 if (err) 601 goto give_sigsegv; 602 603 setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]); 604 if (err) 605 goto give_sigsegv; 606 607 if (TARGET_NSIG_WORDS > 1) { 608 err |= __copy_to_user(frame->extramask, &set->sig[1], 609 sizeof(frame->extramask)); 610 } 611 if (err) 612 goto give_sigsegv; 613 614 /* Set up to return from userspace. If provided, use a stub 615 already in userspace. */ 616 if (ka->sa.sa_flags & TARGET_SA_RESTORER) { 617 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); 618 } else { 619 err |= __put_user(frame->retcode, &frame->pretcode); 620 /* This is popl %eax ; movl $,%eax ; int $0x80 */ 621 err |= __put_user(0xb858, (short *)(frame->retcode+0)); 622 err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2)); 623 err |= __put_user(0x80cd, (short *)(frame->retcode+6)); 624 } 625 626 if (err) 627 goto give_sigsegv; 628 629 /* Set up registers for signal handler */ 630 env->regs[R_ESP] = (unsigned long) frame; 631 env->eip = (unsigned long) ka->sa._sa_handler; 632 633 cpu_x86_load_seg(env, R_DS, __USER_DS); 634 cpu_x86_load_seg(env, R_ES, __USER_DS); 635 cpu_x86_load_seg(env, R_SS, __USER_DS); 636 cpu_x86_load_seg(env, R_CS, __USER_CS); 637 env->eflags &= ~TF_MASK; 638 639 return; 640 641 give_sigsegv: 642 if (sig == TARGET_SIGSEGV) 643 ka->sa._sa_handler = TARGET_SIG_DFL; 644 force_sig(TARGET_SIGSEGV /* , current */); 645 } 646 647 static void setup_rt_frame(int sig, struct emulated_sigaction *ka, 648 target_siginfo_t *info, 649 target_sigset_t *set, CPUX86State *env) 650 { 651 struct rt_sigframe *frame; 652 int err = 0; 653 654 frame = get_sigframe(ka, env, sizeof(*frame)); 655 656 #if 0 657 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 658 goto give_sigsegv; 659 #endif 660 661 err |= __put_user((/*current->exec_domain 662 && current->exec_domain->signal_invmap 663 && sig < 32 664 ? current->exec_domain->signal_invmap[sig] 665 : */sig), 666 &frame->sig); 667 err |= __put_user((target_ulong)&frame->info, &frame->pinfo); 668 err |= __put_user((target_ulong)&frame->uc, &frame->puc); 669 err |= copy_siginfo_to_user(&frame->info, info); 670 if (err) 671 goto give_sigsegv; 672 673 /* Create the ucontext. */ 674 err |= __put_user(0, &frame->uc.uc_flags); 675 err |= __put_user(0, &frame->uc.uc_link); 676 err |= __put_user(/*current->sas_ss_sp*/ 0, &frame->uc.uc_stack.ss_sp); 677 err |= __put_user(/* sas_ss_flags(regs->esp) */ 0, 678 &frame->uc.uc_stack.ss_flags); 679 err |= __put_user(/* current->sas_ss_size */ 0, &frame->uc.uc_stack.ss_size); 680 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, 681 env, set->sig[0]); 682 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 683 if (err) 684 goto give_sigsegv; 685 686 /* Set up to return from userspace. If provided, use a stub 687 already in userspace. */ 688 if (ka->sa.sa_flags & TARGET_SA_RESTORER) { 689 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); 690 } else { 691 err |= __put_user(frame->retcode, &frame->pretcode); 692 /* This is movl $,%eax ; int $0x80 */ 693 err |= __put_user(0xb8, (char *)(frame->retcode+0)); 694 err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1)); 695 err |= __put_user(0x80cd, (short *)(frame->retcode+5)); 696 } 697 698 if (err) 699 goto give_sigsegv; 700 701 /* Set up registers for signal handler */ 702 env->regs[R_ESP] = (unsigned long) frame; 703 env->eip = (unsigned long) ka->sa._sa_handler; 704 705 cpu_x86_load_seg(env, R_DS, __USER_DS); 706 cpu_x86_load_seg(env, R_ES, __USER_DS); 707 cpu_x86_load_seg(env, R_SS, __USER_DS); 708 cpu_x86_load_seg(env, R_CS, __USER_CS); 709 env->eflags &= ~TF_MASK; 710 711 return; 712 713 give_sigsegv: 714 if (sig == TARGET_SIGSEGV) 715 ka->sa._sa_handler = TARGET_SIG_DFL; 716 force_sig(TARGET_SIGSEGV /* , current */); 717 } 718 719 static int 720 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax) 721 { 722 unsigned int err = 0; 723 724 725 726 #define COPY(x) err |= __get_user(regs->x, &sc->x) 727 728 #define COPY_SEG(seg) \ 729 { unsigned short tmp; \ 730 err |= __get_user(tmp, &sc->seg); \ 731 regs->x##seg = tmp; } 732 733 #define COPY_SEG_STRICT(seg) \ 734 { unsigned short tmp; \ 735 err |= __get_user(tmp, &sc->seg); \ 736 regs->x##seg = tmp|3; } 737 738 #define GET_SEG(seg) \ 739 { unsigned short tmp; \ 740 err |= __get_user(tmp, &sc->seg); \ 741 loadsegment(seg,tmp); } 742 743 cpu_x86_load_seg(env, R_GS, lduw(&sc->gs)); 744 cpu_x86_load_seg(env, R_FS, lduw(&sc->fs)); 745 cpu_x86_load_seg(env, R_ES, lduw(&sc->es)); 746 cpu_x86_load_seg(env, R_DS, lduw(&sc->ds)); 747 748 env->regs[R_EDI] = ldl(&sc->edi); 749 env->regs[R_ESI] = ldl(&sc->esi); 750 env->regs[R_EBP] = ldl(&sc->ebp); 751 env->regs[R_ESP] = ldl(&sc->esp); 752 env->regs[R_EBX] = ldl(&sc->ebx); 753 env->regs[R_EDX] = ldl(&sc->edx); 754 env->regs[R_ECX] = ldl(&sc->ecx); 755 env->eip = ldl(&sc->eip); 756 757 cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3); 758 cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3); 759 760 { 761 unsigned int tmpflags; 762 tmpflags = ldl(&sc->eflags); 763 env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5); 764 // regs->orig_eax = -1; /* disable syscall checks */ 765 } 766 767 #if 0 768 { 769 struct _fpstate * buf; 770 err |= __get_user(buf, &sc->fpstate); 771 if (buf) { 772 if (verify_area(VERIFY_READ, buf, sizeof(*buf))) 773 goto badframe; 774 err |= restore_i387(buf); 775 } 776 } 777 #endif 778 *peax = ldl(&sc->eax); 779 return err; 780 #if 0 781 badframe: 782 return 1; 783 #endif 784 } 785 786 long do_sigreturn(CPUX86State *env) 787 { 788 struct sigframe *frame = (struct sigframe *)(env->regs[R_ESP] - 8); 789 target_sigset_t target_set; 790 sigset_t set; 791 int eax, i; 792 793 #if defined(DEBUG_SIGNAL) 794 fprintf(stderr, "do_sigreturn\n"); 795 #endif 796 /* set blocked signals */ 797 target_set.sig[0] = frame->sc.oldmask; 798 for(i = 1; i < TARGET_NSIG_WORDS; i++) 799 target_set.sig[i] = frame->extramask[i - 1]; 800 801 target_to_host_sigset(&set, &target_set); 802 sigprocmask(SIG_SETMASK, &set, NULL); 803 804 /* restore registers */ 805 if (restore_sigcontext(env, &frame->sc, &eax)) 806 goto badframe; 807 return eax; 808 809 badframe: 810 force_sig(TARGET_SIGSEGV); 811 return 0; 812 } 813 814 long do_rt_sigreturn(CPUX86State *env) 815 { 816 struct rt_sigframe *frame = (struct rt_sigframe *)(env->regs[R_ESP] - 4); 817 target_sigset_t target_set; 818 sigset_t set; 819 // stack_t st; 820 int eax; 821 822 #if 0 823 if (verify_area(VERIFY_READ, frame, sizeof(*frame))) 824 goto badframe; 825 #endif 826 memcpy(&target_set, &frame->uc.uc_sigmask, sizeof(target_sigset_t)); 827 828 target_to_host_sigset(&set, &target_set); 829 sigprocmask(SIG_SETMASK, &set, NULL); 830 831 if (restore_sigcontext(env, &frame->uc.uc_mcontext, &eax)) 832 goto badframe; 833 834 #if 0 835 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) 836 goto badframe; 837 /* It is more difficult to avoid calling this function than to 838 call it and ignore errors. */ 839 do_sigaltstack(&st, NULL, regs->esp); 840 #endif 841 return eax; 842 843 badframe: 844 force_sig(TARGET_SIGSEGV); 845 return 0; 846 } 847 848 #endif 849 850 void process_pending_signals(void *cpu_env) 851 { 852 int sig; 853 target_ulong handler; 854 sigset_t set, old_set; 855 target_sigset_t target_old_set; 856 struct emulated_sigaction *k; 857 struct sigqueue *q; 858 859 if (!signal_pending) 860 return; 861 862 k = sigact_table; 863 for(sig = 1; sig <= TARGET_NSIG; sig++) { 864 if (k->pending) 865 goto handle_signal; 866 k++; 867 } 868 /* if no signal is pending, just return */ 869 signal_pending = 0; 870 return; 871 872 handle_signal: 873 #ifdef DEBUG_SIGNAL 874 fprintf(stderr, "qemu: process signal %d\n", sig); 875 #endif 876 /* dequeue signal */ 877 q = k->first; 878 k->first = q->next; 879 if (!k->first) 880 k->pending = 0; 881 882 handler = k->sa._sa_handler; 883 if (handler == TARGET_SIG_DFL) { 884 /* default handler : ignore some signal. The other are fatal */ 885 if (sig != TARGET_SIGCHLD && 886 sig != TARGET_SIGURG && 887 sig != TARGET_SIGWINCH) { 888 force_sig(sig); 889 } 890 } else if (handler == TARGET_SIG_IGN) { 891 /* ignore sig */ 892 } else if (handler == TARGET_SIG_ERR) { 893 force_sig(sig); 894 } else { 895 /* compute the blocked signals during the handler execution */ 896 target_to_host_sigset(&set, &k->sa.sa_mask); 897 /* SA_NODEFER indicates that the current signal should not be 898 blocked during the handler */ 899 if (!(k->sa.sa_flags & TARGET_SA_NODEFER)) 900 sigaddset(&set, target_to_host_signal(sig)); 901 902 /* block signals in the handler using Linux */ 903 sigprocmask(SIG_BLOCK, &set, &old_set); 904 /* save the previous blocked signal state to restore it at the 905 end of the signal execution (see do_sigreturn) */ 906 host_to_target_sigset(&target_old_set, &old_set); 907 908 /* if the CPU is in VM86 mode, we restore the 32 bit values */ 909 #ifdef TARGET_I386 910 { 911 CPUX86State *env = cpu_env; 912 if (env->eflags & VM_MASK) 913 save_v86_state(env); 914 } 915 #endif 916 /* prepare the stack frame of the virtual CPU */ 917 if (k->sa.sa_flags & TARGET_SA_SIGINFO) 918 setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env); 919 else 920 setup_frame(sig, k, &target_old_set, cpu_env); 921 if (k->sa.sa_flags & TARGET_SA_RESETHAND) 922 k->sa._sa_handler = TARGET_SIG_DFL; 923 } 924 if (q != &k->info) 925 free_sigqueue(q); 926 } 927 928 929