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