arch/i386/kernel/signal.c

   1 /*
   2  *  linux/arch/i386/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
   7  */
   8
   9 #include <linux/config.h>
  10
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/smp.h>
  14 #include <linux/smp_lock.h>
  15 #include <linux/kernel.h>
  16 #include <linux/signal.h>
  17 #include <linux/errno.h>
  18 #include <linux/wait.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/unistd.h>
  21 #include <linux/stddef.h>
  22 #include <asm/ucontext.h>
  23 #include <asm/uaccess.h>
  24
  25 #define DEBUG_SIG 0
  26
  27 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  28
  29 asmlinkage int sys_wait4(pid_t pid, unsigned long *stat_addr,
  30                          int options, unsigned long *ru);
  31 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
  32
  33 /*
  34  * Atomically swap in the new signal mask, and wait for a signal.
  35  */
  36 asmlinkage int
  37 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
  38 {
  39         struct pt_regs * regs = (struct pt_regs *) &history0;
  40         sigset_t saveset;
  41
  42         mask &= _BLOCKABLE;
  43         spin_lock_irq(&current->sigmask_lock);
  44         saveset = current->blocked;
  45         siginitset(&current->blocked, mask);
  46         recalc_sigpending(current);
  47         spin_unlock_irq(&current->sigmask_lock);
  48
  49         regs->eax = -EINTR;
  50         while (1) {
  51                 current->state = TASK_INTERRUPTIBLE;
  52                 schedule();
  53                 if (do_signal(&saveset, regs))
  54                         return -EINTR;
  55         }
  56 }
  57
  58 asmlinkage int
  59 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize)
  60 {
  61         struct pt_regs * regs = (struct pt_regs *) &unewset;
  62         sigset_t saveset, newset;
  63
  64         /* XXX: Don't preclude handling different sized sigset_t's.  */
  65         if (sigsetsize != sizeof(sigset_t))
  66                 return -EINVAL;
  67
  68         if (copy_from_user(&newset, unewset, sizeof(newset)))
  69                 return -EFAULT;
  70         sigdelsetmask(&newset, ~_BLOCKABLE);
  71
  72         spin_lock_irq(&current->sigmask_lock);
  73         saveset = current->blocked;
  74         current->blocked = newset;
  75         recalc_sigpending(current);
  76         spin_unlock_irq(&current->sigmask_lock);
  77
  78         regs->eax = -EINTR;
  79         while (1) {
  80                 current->state = TASK_INTERRUPTIBLE;
  81                 schedule();
  82                 if (do_signal(&saveset, regs))
  83                         return -EINTR;
  84         }
  85 }
  86
  87 asmlinkage int
  88 sys_sigaction(int sig, const struct old_sigaction *act,
  89               struct old_sigaction *oact)
  90 {
  91         struct k_sigaction new_ka, old_ka;
  92         int ret;
  93
  94         if (act) {
  95                 old_sigset_t mask;
  96                 if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
  97                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  98                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
  99                         return -EFAULT;
 100                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 101                 __get_user(mask, &act->sa_mask);
 102                 siginitset(&new_ka.sa.sa_mask, mask);
 103         }
 104
 105         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 106
 107         if (!ret && oact) {
 108                 if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
 109                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 110                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 111                         return -EFAULT;
 112                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 113                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 114         }
 115
 116         return ret;
 117 }
 118
 119 asmlinkage int
 120 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
 121 {
 122         struct pt_regs *regs = (struct pt_regs *) &uss;
 123         return do_sigaltstack(uss, uoss, regs->esp);
 124 }
 125
 126
 127 /*
 128  * Do a signal return; undo the signal stack.
 129  */
 130
 131 struct sigframe
 132 {
 133         char *pretcode;
 134         int sig;
 135         struct sigcontext sc;
 136         struct _fpstate fpstate;
 137         unsigned long extramask[_NSIG_WORDS-1];
 138         char retcode[8];
 139 };
 140
 141 struct rt_sigframe
 142 {
 143         char *pretcode;
 144         int sig;
 145         struct siginfo *pinfo;
 146         void *puc;
 147         struct siginfo info;
 148         struct ucontext uc;
 149         struct _fpstate fpstate;
 150         char retcode[8];
 151 };
 152
 153
 154 static inline int restore_i387_hard(struct _fpstate *buf)
 155 {
 156         if (current->flags & PF_USEDFPU) {
 157                 current->flags &= ~PF_USEDFPU;
 158                 stts();
 159         }
 160         return __copy_from_user(&current->tss.i387.hard, buf, sizeof(*buf));
 161 }
 162
 163 static inline int restore_i387(struct _fpstate *buf)
 164 {
 165         int err;
 166 #ifndef CONFIG_MATH_EMULATION
 167         err = restore_i387_hard(buf);
 168 #else
 169         if (boot_cpu_data.hard_math)
 170                 err = restore_i387_hard(buf);
 171         else
 172                 err = restore_i387_soft(&current->tss.i387.soft, buf);
 173 #endif
 174         current->used_math = 1;
 175         return err;
 176 }
 177
 178 static int
 179 restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *peax)
 180 {
 181         unsigned int err = 0;
 182
 183 #define COPY(x)         err |= __get_user(regs->x, &sc->x)
 184
 185 #define COPY_SEG(seg)                                                   \
 186         { unsigned short tmp;                                           \
 187           err |= __get_user(tmp, &sc->seg);                             \
 188           regs->x##seg = tmp; }
 189
 190 #define COPY_SEG_STRICT(seg)                                            \
 191         { unsigned short tmp;                                           \
 192           err |= __get_user(tmp, &sc->seg);                             \
 193           regs->x##seg = tmp|3; }
 194
 195 #define GET_SEG(seg)                                                    \
 196         { unsigned short tmp;                                           \
 197           err |= __get_user(tmp, &sc->seg);                             \
 198           loadsegment(seg,tmp); }
 199
 200         GET_SEG(gs);
 201         GET_SEG(fs);
 202         COPY_SEG(es);
 203         COPY_SEG(ds);
 204         COPY(edi);
 205         COPY(esi);
 206         COPY(ebp);
 207         COPY(esp);
 208         COPY(ebx);
 209         COPY(edx);
 210         COPY(ecx);
 211         COPY(eip);
 212         COPY_SEG_STRICT(cs);
 213         COPY_SEG_STRICT(ss);
 214
 215         {
 216                 unsigned int tmpflags;
 217                 err |= __get_user(tmpflags, &sc->eflags);
 218                 regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
 219                 regs->orig_eax = -1;            /* disable syscall checks */
 220         }
 221
 222         {
 223                 struct _fpstate * buf;
 224                 err |= __get_user(buf, &sc->fpstate);
 225                 if (buf) {
 226                         if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
 227                                 goto badframe;
 228                         err |= restore_i387(buf);
 229                 }
 230         }
 231
 232         err |= __get_user(*peax, &sc->eax);
 233         return err;
 234
 235 badframe:
 236         return 1;
 237 }
 238
 239 asmlinkage int sys_sigreturn(unsigned long __unused)
 240 {
 241         struct pt_regs *regs = (struct pt_regs *) &__unused;
 242         struct sigframe *frame = (struct sigframe *)(regs->esp - 8);
 243         sigset_t set;
 244         int eax;
 245
 246         if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
 247                 goto badframe;
 248         if (__get_user(set.sig[0], &frame->sc.oldmask)
 249             || (_NSIG_WORDS > 1
 250                 && __copy_from_user(&set.sig[1], &frame->extramask,
 251                                     sizeof(frame->extramask))))
 252                 goto badframe;
 253
 254         sigdelsetmask(&set, ~_BLOCKABLE);
 255         spin_lock_irq(&current->sigmask_lock);
 256         current->blocked = set;
 257         recalc_sigpending(current);
 258         spin_unlock_irq(&current->sigmask_lock);
 259
 260         if (restore_sigcontext(regs, &frame->sc, &eax))
 261                 goto badframe;
 262         return eax;
 263
 264 badframe:
 265         force_sig(SIGSEGV, current);
 266         return 0;
 267 }
 268
 269 asmlinkage int sys_rt_sigreturn(unsigned long __unused)
 270 {
 271         struct pt_regs *regs = (struct pt_regs *) &__unused;
 272         struct rt_sigframe *frame = (struct rt_sigframe *)(regs->esp - 4);
 273         sigset_t set;
 274         stack_t st;
 275         int eax;
 276
 277         if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
 278                 goto badframe;
 279         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 280                 goto badframe;
 281
 282         sigdelsetmask(&set, ~_BLOCKABLE);
 283         spin_lock_irq(&current->sigmask_lock);
 284         current->blocked = set;
 285         recalc_sigpending(current);
 286         spin_unlock_irq(&current->sigmask_lock);
 287
 288         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
 289                 goto badframe;
 290
 291         if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
 292                 goto badframe;
 293         /* It is more difficult to avoid calling this function than to
 294            call it and ignore errors.  */
 295         do_sigaltstack(&st, NULL, regs->esp);
 296
 297         return eax;
 298
 299 badframe:
 300         force_sig(SIGSEGV, current);
 301         return 0;
 302 }
 303
 304 /*
 305  * Set up a signal frame.
 306  */
 307
 308 static inline int save_i387_hard(struct _fpstate * buf)
 309 {
 310         if (current->flags & PF_USEDFPU) {
 311                 current->flags &= ~PF_USEDFPU;
 312                 __asm__ __volatile__("fnsave %0":"=m"(current->tss.i387.hard));
 313                 stts();
 314         }
 315         asm volatile("fwait");
 316         current->tss.i387.hard.status = current->tss.i387.hard.swd;
 317         if (__copy_to_user(buf, &current->tss.i387.hard, sizeof(*buf)))
 318                 return -1;
 319         return 1;
 320 }
 321
 322 static int save_i387(struct _fpstate *buf)
 323 {
 324         if (!current->used_math)
 325                 return 0;
 326
 327         /* This will cause a "finit" to be triggered by the next
 328            attempted FPU operation by the 'current' process.
 329            */
 330         current->used_math = 0;
 331
 332 #ifndef CONFIG_MATH_EMULATION
 333         return save_i387_hard(buf);
 334 #else
 335         return boot_cpu_data.hard_math ? save_i387_hard(buf)
 336           : save_i387_soft(&current->tss.i387.soft, buf);
 337 #endif
 338 }
 339
 340 static int
 341 setup_sigcontext(struct sigcontext *sc, struct _fpstate *fpstate,
 342                  struct pt_regs *regs, unsigned long mask)
 343 {
 344         int tmp, err = 0;
 345
 346         tmp = 0;
 347         __asm__("movl %%gs,%w0" : "=r"(tmp): "0"(tmp));
 348         err |= __put_user(tmp, (unsigned int *)&sc->gs);
 349         __asm__("movl %%fs,%w0" : "=r"(tmp): "0"(tmp));
 350         err |= __put_user(tmp, (unsigned int *)&sc->fs);
 351
 352         err |= __put_user(regs->xes, (unsigned int *)&sc->es);
 353         err |= __put_user(regs->xds, (unsigned int *)&sc->ds);
 354         err |= __put_user(regs->edi, &sc->edi);
 355         err |= __put_user(regs->esi, &sc->esi);
 356         err |= __put_user(regs->ebp, &sc->ebp);
 357         err |= __put_user(regs->esp, &sc->esp);
 358         err |= __put_user(regs->ebx, &sc->ebx);
 359         err |= __put_user(regs->edx, &sc->edx);
 360         err |= __put_user(regs->ecx, &sc->ecx);
 361         err |= __put_user(regs->eax, &sc->eax);
 362         err |= __put_user(current->tss.trap_no, &sc->trapno);
 363         err |= __put_user(current->tss.error_code, &sc->err);
 364         err |= __put_user(regs->eip, &sc->eip);
 365         err |= __put_user(regs->xcs, (unsigned int *)&sc->cs);
 366         err |= __put_user(regs->eflags, &sc->eflags);
 367         err |= __put_user(regs->esp, &sc->esp_at_signal);
 368         err |= __put_user(regs->xss, (unsigned int *)&sc->ss);
 369
 370         tmp = save_i387(fpstate);
 371         if (tmp < 0)
 372           err = 1;
 373         else
 374           err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
 375
 376         /* non-iBCS2 extensions.. */
 377         err |= __put_user(mask, &sc->oldmask);
 378         err |= __put_user(current->tss.cr2, &sc->cr2);
 379
 380         return err;
 381 }
 382
 383 /*
 384  * Determine which stack to use..
 385  */
 386 static inline void *
 387 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
 388 {
 389         unsigned long esp;
 390
 391         /* Default to using normal stack */
 392         esp = regs->esp;
 393
 394         /* This is the X/Open sanctioned signal stack switching.  */
 395         if (ka->sa.sa_flags & SA_ONSTACK) {
 396                 if (! on_sig_stack(esp))
 397                         esp = current->sas_ss_sp + current->sas_ss_size;
 398         }
 399
 400         /* This is the legacy signal stack switching. */
 401         else if ((regs->xss & 0xffff) != __USER_DS &&
 402                  !(ka->sa.sa_flags & SA_RESTORER) &&
 403                  ka->sa.sa_restorer) {
 404                 esp = (unsigned long) ka->sa.sa_restorer;
 405         }
 406
 407         return (void *)((esp - frame_size) & -8ul);
 408 }
 409
 410 static void setup_frame(int sig, struct k_sigaction *ka,
 411                         sigset_t *set, struct pt_regs * regs)
 412 {
 413         struct sigframe *frame;
 414         int err = 0;
 415
 416         frame = get_sigframe(ka, regs, sizeof(*frame));
 417
 418         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 419                 goto give_sigsegv;
 420
 421         err |= __put_user((current->exec_domain
 422                            && current->exec_domain->signal_invmap
 423                            && sig < 32
 424                            ? current->exec_domain->signal_invmap[sig]
 425                            : sig),
 426                           &frame->sig);
 427
 428         err |= setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
 429
 430         if (_NSIG_WORDS > 1) {
 431                 err |= __copy_to_user(frame->extramask, &set->sig[1],
 432                                       sizeof(frame->extramask));
 433         }
 434
 435         /* Set up to return from userspace.  If provided, use a stub
 436            already in userspace.  */
 437         if (ka->sa.sa_flags & SA_RESTORER) {
 438                 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 439         } else {
 440                 err |= __put_user(frame->retcode, &frame->pretcode);
 441                 /* This is popl %eax ; movl $,%eax ; int $0x80 */
 442                 err |= __put_user(0xb858, (short *)(frame->retcode+0));
 443                 err |= __put_user(__NR_sigreturn, (int *)(frame->retcode+2));
 444                 err |= __put_user(0x80cd, (short *)(frame->retcode+6));
 445         }
 446
 447         if (err)
 448                 goto give_sigsegv;
 449
 450         /* Set up registers for signal handler */
 451         regs->esp = (unsigned long) frame;
 452         regs->eip = (unsigned long) ka->sa.sa_handler;
 453
 454         set_fs(USER_DS);
 455         regs->xds = __USER_DS;
 456         regs->xes = __USER_DS;
 457         regs->xss = __USER_DS;
 458         regs->xcs = __USER_CS;
 459         regs->eflags &= ~TF_MASK;
 460
 461 #if DEBUG_SIG
 462         printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
 463                 current->comm, current->pid, frame, regs->eip, frame->pretcode);
 464 #endif
 465
 466         return;
 467
 468 give_sigsegv:
 469         if (sig == SIGSEGV)
 470                 ka->sa.sa_handler = SIG_DFL;
 471         force_sig(SIGSEGV, current);
 472 }
 473
 474 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 475                            sigset_t *set, struct pt_regs * regs)
 476 {
 477         struct rt_sigframe *frame;
 478         int err = 0;
 479
 480         frame = get_sigframe(ka, regs, sizeof(*frame));
 481
 482         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 483                 goto give_sigsegv;
 484
 485         err |= __put_user((current->exec_domain
 486                            && current->exec_domain->signal_invmap
 487                            && sig < 32
 488                            ? current->exec_domain->signal_invmap[sig]
 489                            : sig),
 490                           &frame->sig);
 491         err |= __put_user(&frame->info, &frame->pinfo);
 492         err |= __put_user(&frame->uc, &frame->puc);
 493         err |= __copy_to_user(&frame->info, info, sizeof(*info));
 494
 495         /* Create the ucontext.  */
 496         err |= __put_user(0, &frame->uc.uc_flags);
 497         err |= __put_user(0, &frame->uc.uc_link);
 498         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 499         err |= __put_user(sas_ss_flags(regs->esp),
 500                           &frame->uc.uc_stack.ss_flags);
 501         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 502         err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
 503                                 regs, set->sig[0]);
 504         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 505
 506         /* Set up to return from userspace.  If provided, use a stub
 507            already in userspace.  */
 508         if (ka->sa.sa_flags & SA_RESTORER) {
 509                 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 510         } else {
 511                 err |= __put_user(frame->retcode, &frame->pretcode);
 512                 /* This is movl $,%eax ; int $0x80 */
 513                 err |= __put_user(0xb8, (char *)(frame->retcode+0));
 514                 err |= __put_user(__NR_rt_sigreturn, (int *)(frame->retcode+1));
 515                 err |= __put_user(0x80cd, (short *)(frame->retcode+5));
 516         }
 517
 518         if (err)
 519                 goto give_sigsegv;
 520
 521         /* Set up registers for signal handler */
 522         regs->esp = (unsigned long) frame;
 523         regs->eip = (unsigned long) ka->sa.sa_handler;
 524
 525         set_fs(USER_DS);
 526         regs->xds = __USER_DS;
 527         regs->xes = __USER_DS;
 528         regs->xss = __USER_DS;
 529         regs->xcs = __USER_CS;
 530         regs->eflags &= ~TF_MASK;
 531
 532 #if DEBUG_SIG
 533         printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
 534                 current->comm, current->pid, frame, regs->eip, frame->pretcode);
 535 #endif
 536
 537         return;
 538
 539 give_sigsegv:
 540         if (sig == SIGSEGV)
 541                 ka->sa.sa_handler = SIG_DFL;
 542         force_sig(SIGSEGV, current);
 543 }
 544
 545 /*
 546  * OK, we're invoking a handler
 547  */
 548
 549 static void
 550 handle_signal(unsigned long sig, struct k_sigaction *ka,
 551               siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
 552 {
 553         /* Are we from a system call? */
 554         if (regs->orig_eax >= 0) {
 555                 /* If so, check system call restarting.. */
 556                 switch (regs->eax) {
 557                         case -ERESTARTNOHAND:
 558                                 regs->eax = -EINTR;
 559                                 break;
 560
 561                         case -ERESTARTSYS:
 562                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 563                                         regs->eax = -EINTR;
 564                                         break;
 565                                 }
 566                         /* fallthrough */
 567                         case -ERESTARTNOINTR:
 568                                 regs->eax = regs->orig_eax;
 569                                 regs->eip -= 2;
 570                 }
 571         }
 572
 573         /* Set up the stack frame */
 574         if (ka->sa.sa_flags & SA_SIGINFO)
 575                 setup_rt_frame(sig, ka, info, oldset, regs);
 576         else
 577                 setup_frame(sig, ka, oldset, regs);
 578
 579         if (ka->sa.sa_flags & SA_ONESHOT)
 580                 ka->sa.sa_handler = SIG_DFL;
 581
 582         if (!(ka->sa.sa_flags & SA_NODEFER)) {
 583                 spin_lock_irq(&current->sigmask_lock);
 584                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 585                 sigaddset(&current->blocked,sig);
 586                 recalc_sigpending(current);
 587                 spin_unlock_irq(&current->sigmask_lock);
 588         }
 589 }
 590
 591 /*
 592  * Note that 'init' is a special process: it doesn't get signals it doesn't
 593  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 594  * mistake.
 595  *
 596  * Note that we go through the signals twice: once to check the signals that
 597  * the kernel can handle, and then we build all the user-level signal handling
 598  * stack-frames in one go after that.
 599  */
 600 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
 601 {
 602         siginfo_t info;
 603         struct k_sigaction *ka;
 604
 605         /*
 606          * We want the common case to go fast, which
 607          * is why we may in certain cases get here from
 608          * kernel mode. Just return without doing anything
 609          * if so.
 610          */
 611         if ((regs->xcs & 3) != 3)
 612                 return 1;
 613
 614         if (!oldset)
 615                 oldset = &current->blocked;
 616
 617         for (;;) {
 618                 unsigned long signr;
 619
 620                 spin_lock_irq(&current->sigmask_lock);
 621                 signr = dequeue_signal(&current->blocked, &info);
 622                 spin_unlock_irq(&current->sigmask_lock);
 623
 624                 if (!signr)
 625                         break;
 626
 627                 if ((current->flags & PF_PTRACED) && signr != SIGKILL) {
 628                         /* Let the debugger run.  */
 629                         current->exit_code = signr;
 630                         current->state = TASK_STOPPED;
 631                         notify_parent(current, SIGCHLD);
 632                         schedule();
 633
 634                         /* We're back.  Did the debugger cancel the sig?  */
 635                         if (!(signr = current->exit_code))
 636                                 continue;
 637                         current->exit_code = 0;
 638
 639                         /* The debugger continued.  Ignore SIGSTOP.  */
 640                         if (signr == SIGSTOP)
 641                                 continue;
 642
 643                         /* Update the siginfo structure.  Is this good?  */
 644                         if (signr != info.si_signo) {
 645                                 info.si_signo = signr;
 646                                 info.si_errno = 0;
 647                                 info.si_code = SI_USER;
 648                                 info.si_pid = current->p_pptr->pid;
 649                                 info.si_uid = current->p_pptr->uid;
 650                         }
 651
 652                         /* If the (new) signal is now blocked, requeue it.  */
 653                         if (sigismember(&current->blocked, signr)) {
 654                                 send_sig_info(signr, &info, current);
 655                                 continue;
 656                         }
 657                 }
 658
 659                 ka = &current->sig->action[signr-1];
 660                 if (ka->sa.sa_handler == SIG_IGN) {
 661                         if (signr != SIGCHLD)
 662                                 continue;
 663                         /* Check for SIGCHLD: it's special.  */
 664                         while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
 665                                 /* nothing */;
 666                         continue;
 667                 }
 668
 669                 if (ka->sa.sa_handler == SIG_DFL) {
 670                         int exit_code = signr;
 671
 672                         /* Init gets no signals it doesn't want.  */
 673                         if (current->pid == 1)
 674                                 continue;
 675
 676                         switch (signr) {
 677                         case SIGCONT: case SIGCHLD: case SIGWINCH:
 678                                 continue;
 679
 680                         case SIGTSTP: case SIGTTIN: case SIGTTOU:
 681                                 if (is_orphaned_pgrp(current->pgrp))
 682                                         continue;
 683                                 /* FALLTHRU */
 684
 685                         case SIGSTOP:
 686                                 current->state = TASK_STOPPED;
 687                                 current->exit_code = signr;
 688                                 if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
 689                                         notify_parent(current, SIGCHLD);
 690                                 schedule();
 691                                 continue;
 692
 693                         case SIGQUIT: case SIGILL: case SIGTRAP:
 694                         case SIGABRT: case SIGFPE: case SIGSEGV:
 695                                 lock_kernel();
 696                                 if (current->binfmt
 697                                     && current->binfmt->core_dump
 698                                     && current->binfmt->core_dump(signr, regs))
 699                                         exit_code |= 0x80;
 700                                 unlock_kernel();
 701                                 /* FALLTHRU */
 702
 703                         default:
 704                                 lock_kernel();
 705                                 sigaddset(&current->signal, signr);
 706                                 current->flags |= PF_SIGNALED;
 707                                 do_exit(exit_code);
 708                                 /* NOTREACHED */
 709                         }
 710                 }
 711
 712                 /* Whee!  Actually deliver the signal.  */
 713                 handle_signal(signr, ka, &info, oldset, regs);
 714                 return 1;
 715         }
 716
 717         /* Did we come from a system call? */
 718         if (regs->orig_eax >= 0) {
 719                 /* Restart the system call - no handlers present */
 720                 if (regs->eax == -ERESTARTNOHAND ||
 721                     regs->eax == -ERESTARTSYS ||
 722                     regs->eax == -ERESTARTNOINTR) {
 723                         regs->eax = regs->orig_eax;
 724                         regs->eip -= 2;
 725                 }
 726         }
 727         return 0;
 728 }