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); 539 540 cpu_x86_fsave(env, (void *)fpstate, 1); 541 fpstate->status = fpstate->sw; 542 err |= __put_user(0xffff, &fpstate->magic); 543 err |= __put_user(fpstate, &sc->fpstate); 544 545 /* non-iBCS2 extensions.. */ 546 err |= __put_user(mask, &sc->oldmask); 547 err |= __put_user(env->cr2, &sc->cr2); 548 return err; 549 } 550 551 /* 552 * Determine which stack to use.. 553 */ 554 555 static inline void * 556 get_sigframe(struct emulated_sigaction *ka, CPUX86State *env, size_t frame_size) 557 { 558 unsigned long esp; 559 560 /* Default to using normal stack */ 561 esp = env->regs[R_ESP]; 562 #if 0 563 /* This is the X/Open sanctioned signal stack switching. */ 564 if (ka->sa.sa_flags & SA_ONSTACK) { 565 if (sas_ss_flags(esp) == 0) 566 esp = current->sas_ss_sp + current->sas_ss_size; 567 } 568 569 /* This is the legacy signal stack switching. */ 570 else if ((regs->xss & 0xffff) != __USER_DS && 571 !(ka->sa.sa_flags & SA_RESTORER) && 572 ka->sa.sa_restorer) { 573 esp = (unsigned long) ka->sa.sa_restorer; 574 } 575 #endif 576 return (void *)((esp - frame_size) & -8ul); 577 } 578 579 static void setup_frame(int sig, struct emulated_sigaction *ka, 580 target_sigset_t *set, CPUX86State *env) 581 { 582 struct sigframe *frame; 583 int err = 0; 584 585 frame = get_sigframe(ka, env, sizeof(*frame)); 586 587 #if 0 588 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 589 goto give_sigsegv; 590 #endif 591 err |= __put_user((/*current->exec_domain 592 && current->exec_domain->signal_invmap 593 && sig < 32 594 ? current->exec_domain->signal_invmap[sig] 595 : */ sig), 596 &frame->sig); 597 if (err) 598 goto give_sigsegv; 599 600 setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0]); 601 if (err) 602 goto give_sigsegv; 603 604 if (TARGET_NSIG_WORDS > 1) { 605 err |= __copy_to_user(frame->extramask, &set->sig[1], 606 sizeof(frame->extramask)); 607 } 608 if (err) 609 goto give_sigsegv; 610 611 /* Set up to return from userspace. If provided, use a stub 612 already in userspace. */ 613 if (ka->sa.sa_flags & TARGET_SA_RESTORER) { 614 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); 615 } else { 616 err |= __put_user(frame->retcode, &frame->pretcode); 617 /* This is popl %eax ; movl $,%eax ; int $0x80 */ 618 err |= __put_user(0xb858, (short *)(frame->retcode+0)); 619 err |= __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2)); 620 err |= __put_user(0x80cd, (short *)(frame->retcode+6)); 621 } 622 623 if (err) 624 goto give_sigsegv; 625 626 /* Set up registers for signal handler */ 627 env->regs[R_ESP] = (unsigned long) frame; 628 env->eip = (unsigned long) ka->sa._sa_handler; 629 630 cpu_x86_load_seg(env, R_DS, __USER_DS); 631 cpu_x86_load_seg(env, R_ES, __USER_DS); 632 cpu_x86_load_seg(env, R_SS, __USER_DS); 633 cpu_x86_load_seg(env, R_CS, __USER_CS); 634 env->eflags &= ~TF_MASK; 635 636 return; 637 638 give_sigsegv: 639 if (sig == TARGET_SIGSEGV) 640 ka->sa._sa_handler = TARGET_SIG_DFL; 641 force_sig(TARGET_SIGSEGV /* , current */); 642 } 643 644 static void setup_rt_frame(int sig, struct emulated_sigaction *ka, 645 target_siginfo_t *info, 646 target_sigset_t *set, CPUX86State *env) 647 { 648 struct rt_sigframe *frame; 649 int err = 0; 650 651 frame = get_sigframe(ka, env, sizeof(*frame)); 652 653 #if 0 654 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 655 goto give_sigsegv; 656 #endif 657 658 err |= __put_user((/*current->exec_domain 659 && current->exec_domain->signal_invmap 660 && sig < 32 661 ? current->exec_domain->signal_invmap[sig] 662 : */sig), 663 &frame->sig); 664 err |= __put_user((target_ulong)&frame->info, &frame->pinfo); 665 err |= __put_user((target_ulong)&frame->uc, &frame->puc); 666 err |= copy_siginfo_to_user(&frame->info, info); 667 if (err) 668 goto give_sigsegv; 669 670 /* Create the ucontext. */ 671 err |= __put_user(0, &frame->uc.uc_flags); 672 err |= __put_user(0, &frame->uc.uc_link); 673 err |= __put_user(/*current->sas_ss_sp*/ 0, &frame->uc.uc_stack.ss_sp); 674 err |= __put_user(/* sas_ss_flags(regs->esp) */ 0, 675 &frame->uc.uc_stack.ss_flags); 676 err |= __put_user(/* current->sas_ss_size */ 0, &frame->uc.uc_stack.ss_size); 677 err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate, 678 env, set->sig[0]); 679 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 680 if (err) 681 goto give_sigsegv; 682 683 /* Set up to return from userspace. If provided, use a stub 684 already in userspace. */ 685 if (ka->sa.sa_flags & TARGET_SA_RESTORER) { 686 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); 687 } else { 688 err |= __put_user(frame->retcode, &frame->pretcode); 689 /* This is movl $,%eax ; int $0x80 */ 690 err |= __put_user(0xb8, (char *)(frame->retcode+0)); 691 err |= __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1)); 692 err |= __put_user(0x80cd, (short *)(frame->retcode+5)); 693 } 694 695 if (err) 696 goto give_sigsegv; 697 698 /* Set up registers for signal handler */ 699 env->regs[R_ESP] = (unsigned long) frame; 700 env->eip = (unsigned long) ka->sa._sa_handler; 701 702 cpu_x86_load_seg(env, R_DS, __USER_DS); 703 cpu_x86_load_seg(env, R_ES, __USER_DS); 704 cpu_x86_load_seg(env, R_SS, __USER_DS); 705 cpu_x86_load_seg(env, R_CS, __USER_CS); 706 env->eflags &= ~TF_MASK; 707 708 return; 709 710 give_sigsegv: 711 if (sig == TARGET_SIGSEGV) 712 ka->sa._sa_handler = TARGET_SIG_DFL; 713 force_sig(TARGET_SIGSEGV /* , current */); 714 } 715 716 static int 717 restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax) 718 { 719 unsigned int err = 0; 720 721 cpu_x86_load_seg(env, R_GS, lduw(&sc->gs)); 722 cpu_x86_load_seg(env, R_FS, lduw(&sc->fs)); 723 cpu_x86_load_seg(env, R_ES, lduw(&sc->es)); 724 cpu_x86_load_seg(env, R_DS, lduw(&sc->ds)); 725 726 env->regs[R_EDI] = ldl(&sc->edi); 727 env->regs[R_ESI] = ldl(&sc->esi); 728 env->regs[R_EBP] = ldl(&sc->ebp); 729 env->regs[R_ESP] = ldl(&sc->esp); 730 env->regs[R_EBX] = ldl(&sc->ebx); 731 env->regs[R_EDX] = ldl(&sc->edx); 732 env->regs[R_ECX] = ldl(&sc->ecx); 733 env->eip = ldl(&sc->eip); 734 735 cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3); 736 cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3); 737 738 { 739 unsigned int tmpflags; 740 tmpflags = ldl(&sc->eflags); 741 env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5); 742 // regs->orig_eax = -1; /* disable syscall checks */ 743 } 744 745 { 746 struct _fpstate * buf; 747 buf = (void *)ldl(&sc->fpstate); 748 if (buf) { 749 #if 0 750 if (verify_area(VERIFY_READ, buf, sizeof(*buf))) 751 goto badframe; 752 #endif 753 cpu_x86_frstor(env, (void *)buf, 1); 754 } 755 } 756 757 *peax = ldl(&sc->eax); 758 return err; 759 #if 0 760 badframe: 761 return 1; 762 #endif 763 } 764 765 long do_sigreturn(CPUX86State *env) 766 { 767 struct sigframe *frame = (struct sigframe *)(env->regs[R_ESP] - 8); 768 target_sigset_t target_set; 769 sigset_t set; 770 int eax, i; 771 772 #if defined(DEBUG_SIGNAL) 773 fprintf(stderr, "do_sigreturn\n"); 774 #endif 775 /* set blocked signals */ 776 target_set.sig[0] = frame->sc.oldmask; 777 for(i = 1; i < TARGET_NSIG_WORDS; i++) 778 target_set.sig[i] = frame->extramask[i - 1]; 779 780 target_to_host_sigset(&set, &target_set); 781 sigprocmask(SIG_SETMASK, &set, NULL); 782 783 /* restore registers */ 784 if (restore_sigcontext(env, &frame->sc, &eax)) 785 goto badframe; 786 return eax; 787 788 badframe: 789 force_sig(TARGET_SIGSEGV); 790 return 0; 791 } 792 793 long do_rt_sigreturn(CPUX86State *env) 794 { 795 struct rt_sigframe *frame = (struct rt_sigframe *)(env->regs[R_ESP] - 4); 796 target_sigset_t target_set; 797 sigset_t set; 798 // stack_t st; 799 int eax; 800 801 #if 0 802 if (verify_area(VERIFY_READ, frame, sizeof(*frame))) 803 goto badframe; 804 #endif 805 memcpy(&target_set, &frame->uc.uc_sigmask, sizeof(target_sigset_t)); 806 807 target_to_host_sigset(&set, &target_set); 808 sigprocmask(SIG_SETMASK, &set, NULL); 809 810 if (restore_sigcontext(env, &frame->uc.uc_mcontext, &eax)) 811 goto badframe; 812 813 #if 0 814 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) 815 goto badframe; 816 /* It is more difficult to avoid calling this function than to 817 call it and ignore errors. */ 818 do_sigaltstack(&st, NULL, regs->esp); 819 #endif 820 return eax; 821 822 badframe: 823 force_sig(TARGET_SIGSEGV); 824 return 0; 825 } 826 827 #endif 828 829 void process_pending_signals(void *cpu_env) 830 { 831 int sig; 832 target_ulong handler; 833 sigset_t set, old_set; 834 target_sigset_t target_old_set; 835 struct emulated_sigaction *k; 836 struct sigqueue *q; 837 838 if (!signal_pending) 839 return; 840 841 k = sigact_table; 842 for(sig = 1; sig <= TARGET_NSIG; sig++) { 843 if (k->pending) 844 goto handle_signal; 845 k++; 846 } 847 /* if no signal is pending, just return */ 848 signal_pending = 0; 849 return; 850 851 handle_signal: 852 #ifdef DEBUG_SIGNAL 853 fprintf(stderr, "qemu: process signal %d\n", sig); 854 #endif 855 /* dequeue signal */ 856 q = k->first; 857 k->first = q->next; 858 if (!k->first) 859 k->pending = 0; 860 861 handler = k->sa._sa_handler; 862 if (handler == TARGET_SIG_DFL) { 863 /* default handler : ignore some signal. The other are fatal */ 864 if (sig != TARGET_SIGCHLD && 865 sig != TARGET_SIGURG && 866 sig != TARGET_SIGWINCH) { 867 force_sig(sig); 868 } 869 } else if (handler == TARGET_SIG_IGN) { 870 /* ignore sig */ 871 } else if (handler == TARGET_SIG_ERR) { 872 force_sig(sig); 873 } else { 874 /* compute the blocked signals during the handler execution */ 875 target_to_host_sigset(&set, &k->sa.sa_mask); 876 /* SA_NODEFER indicates that the current signal should not be 877 blocked during the handler */ 878 if (!(k->sa.sa_flags & TARGET_SA_NODEFER)) 879 sigaddset(&set, target_to_host_signal(sig)); 880 881 /* block signals in the handler using Linux */ 882 sigprocmask(SIG_BLOCK, &set, &old_set); 883 /* save the previous blocked signal state to restore it at the 884 end of the signal execution (see do_sigreturn) */ 885 host_to_target_sigset(&target_old_set, &old_set); 886 887 /* if the CPU is in VM86 mode, we restore the 32 bit values */ 888 #ifdef TARGET_I386 889 { 890 CPUX86State *env = cpu_env; 891 if (env->eflags & VM_MASK) 892 save_v86_state(env); 893 } 894 #endif 895 /* prepare the stack frame of the virtual CPU */ 896 if (k->sa.sa_flags & TARGET_SA_SIGINFO) 897 setup_rt_frame(sig, k, &q->info, &target_old_set, cpu_env); 898 else 899 setup_frame(sig, k, &target_old_set, cpu_env); 900 if (k->sa.sa_flags & TARGET_SA_RESETHAND) 901 k->sa._sa_handler = TARGET_SIG_DFL; 902 } 903 if (q != &k->info) 904 free_sigqueue(q); 905 } 906 907 908