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