arch/m68knommu/kernel/signal.c

   1 /*
   2  *  linux/arch/m68knommu/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file COPYING in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 /*
  12  * Linux/m68k support by Hamish Macdonald
  13  *
  14  * 68060 fixes by Jesper Skov
  15  *
  16  * 1997-12-01  Modified for POSIX.1b signals by Andreas Schwab
  17  *
  18  * mathemu support by Roman Zippel
  19  *  (Note: fpstate in the signal context is completely ignored for the emulator
  20  *         and the internal floating point format is put on stack)
  21  */
  22
  23 /*
  24  * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
  25  * Atari :-) Current limitation: Only one sigstack can be active at one time.
  26  * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
  27  * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
  28  * signal handlers!
  29  */
  30
  31 #include <linux/sched.h>
  32 #include <linux/mm.h>
  33 #include <linux/kernel.h>
  34 #include <linux/signal.h>
  35 #include <linux/syscalls.h>
  36 #include <linux/errno.h>
  37 #include <linux/wait.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/unistd.h>
  40 #include <linux/stddef.h>
  41 #include <linux/highuid.h>
  42 #include <linux/tty.h>
  43 #include <linux/personality.h>
  44 #include <linux/binfmts.h>
  45
  46 #include <asm/setup.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/pgtable.h>
  49 #include <asm/traps.h>
  50 #include <asm/ucontext.h>
  51
  52 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  53
  54 void ret_from_user_signal(void);
  55 void ret_from_user_rt_signal(void);
  56 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
  57
  58 /*
  59  * Atomically swap in the new signal mask, and wait for a signal.
  60  */
  61 asmlinkage int do_sigsuspend(struct pt_regs *regs)
  62 {
  63         old_sigset_t mask = regs->d3;
  64         sigset_t saveset;
  65
  66         mask &= _BLOCKABLE;
  67         spin_lock_irq(&current->sighand->siglock);
  68         saveset = current->blocked;
  69         siginitset(&current->blocked, mask);
  70         recalc_sigpending();
  71         spin_unlock_irq(&current->sighand->siglock);
  72
  73         regs->d0 = -EINTR;
  74         while (1) {
  75                 current->state = TASK_INTERRUPTIBLE;
  76                 schedule();
  77                 if (do_signal(&saveset, regs))
  78                         return -EINTR;
  79         }
  80 }
  81
  82 asmlinkage int
  83 do_rt_sigsuspend(struct pt_regs *regs)
  84 {
  85         sigset_t *unewset = (sigset_t *)regs->d1;
  86         size_t sigsetsize = (size_t)regs->d2;
  87         sigset_t saveset, newset;
  88
  89         /* XXX: Don't preclude handling different sized sigset_t's.  */
  90         if (sigsetsize != sizeof(sigset_t))
  91                 return -EINVAL;
  92
  93         if (copy_from_user(&newset, unewset, sizeof(newset)))
  94                 return -EFAULT;
  95         sigdelsetmask(&newset, ~_BLOCKABLE);
  96
  97         spin_lock_irq(&current->sighand->siglock);
  98         saveset = current->blocked;
  99         current->blocked = newset;
 100         recalc_sigpending();
 101         spin_unlock_irq(&current->sighand->siglock);
 102
 103         regs->d0 = -EINTR;
 104         while (1) {
 105                 current->state = TASK_INTERRUPTIBLE;
 106                 schedule();
 107                 if (do_signal(&saveset, regs))
 108                         return -EINTR;
 109         }
 110 }
 111
 112 asmlinkage int
 113 sys_sigaction(int sig, const struct old_sigaction *act,
 114               struct old_sigaction *oact)
 115 {
 116         struct k_sigaction new_ka, old_ka;
 117         int ret;
 118
 119         if (act) {
 120                 old_sigset_t mask;
 121                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 122                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 123                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 124                         return -EFAULT;
 125                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 126                 __get_user(mask, &act->sa_mask);
 127                 siginitset(&new_ka.sa.sa_mask, mask);
 128         }
 129
 130         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 131
 132         if (!ret && oact) {
 133                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 134                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 135                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 136                         return -EFAULT;
 137                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 138                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 139         }
 140
 141         return ret;
 142 }
 143
 144 asmlinkage int
 145 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
 146 {
 147         return do_sigaltstack(uss, uoss, rdusp());
 148 }
 149
 150
 151 /*
 152  * Do a signal return; undo the signal stack.
 153  *
 154  * Keep the return code on the stack quadword aligned!
 155  * That makes the cache flush below easier.
 156  */
 157
 158 struct sigframe
 159 {
 160         char *pretcode;
 161         int sig;
 162         int code;
 163         struct sigcontext *psc;
 164         char retcode[8];
 165         unsigned long extramask[_NSIG_WORDS-1];
 166         struct sigcontext sc;
 167 };
 168
 169 struct rt_sigframe
 170 {
 171         char *pretcode;
 172         int sig;
 173         struct siginfo *pinfo;
 174         void *puc;
 175         char retcode[8];
 176         struct siginfo info;
 177         struct ucontext uc;
 178 };
 179
 180 #ifdef CONFIG_FPU
 181
 182 static unsigned char fpu_version = 0;   /* version number of fpu, set by setup_frame */
 183
 184 static inline int restore_fpu_state(struct sigcontext *sc)
 185 {
 186         int err = 1;
 187
 188         if (FPU_IS_EMU) {
 189             /* restore registers */
 190             memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
 191             memcpy(current->thread.fp, sc->sc_fpregs, 24);
 192             return 0;
 193         }
 194
 195         if (sc->sc_fpstate[0]) {
 196             /* Verify the frame format.  */
 197             if (sc->sc_fpstate[0] != fpu_version)
 198                 goto out;
 199
 200             __asm__ volatile (".chip 68k/68881\n\t"
 201                               "fmovemx %0,%/fp0-%/fp1\n\t"
 202                               "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t"
 203                               ".chip 68k"
 204                               : /* no outputs */
 205                               : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl));
 206         }
 207         __asm__ volatile (".chip 68k/68881\n\t"
 208                           "frestore %0\n\t"
 209                           ".chip 68k" : : "m" (*sc->sc_fpstate));
 210         err = 0;
 211
 212 out:
 213         return err;
 214 }
 215
 216 #define FPCONTEXT_SIZE  216
 217 #define uc_fpstate      uc_filler[0]
 218 #define uc_formatvec    uc_filler[FPCONTEXT_SIZE/4]
 219 #define uc_extra        uc_filler[FPCONTEXT_SIZE/4+1]
 220
 221 static inline int rt_restore_fpu_state(struct ucontext *uc)
 222 {
 223         unsigned char fpstate[FPCONTEXT_SIZE];
 224         int context_size = 0;
 225         fpregset_t fpregs;
 226         int err = 1;
 227
 228         if (FPU_IS_EMU) {
 229                 /* restore fpu control register */
 230                 if (__copy_from_user(current->thread.fpcntl,
 231                                 &uc->uc_mcontext.fpregs.f_pcr, 12))
 232                         goto out;
 233                 /* restore all other fpu register */
 234                 if (__copy_from_user(current->thread.fp,
 235                                 uc->uc_mcontext.fpregs.f_fpregs, 96))
 236                         goto out;
 237                 return 0;
 238         }
 239
 240         if (__get_user(*(long *)fpstate, (long *)&uc->uc_fpstate))
 241                 goto out;
 242         if (fpstate[0]) {
 243                 context_size = fpstate[1];
 244
 245                 /* Verify the frame format.  */
 246                 if (fpstate[0] != fpu_version)
 247                         goto out;
 248                 if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
 249                      sizeof(fpregs)))
 250                         goto out;
 251                 __asm__ volatile (".chip 68k/68881\n\t"
 252                                   "fmovemx %0,%/fp0-%/fp7\n\t"
 253                                   "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t"
 254                                   ".chip 68k"
 255                                   : /* no outputs */
 256                                   : "m" (*fpregs.f_fpregs),
 257                                     "m" (fpregs.f_pcr));
 258         }
 259         if (context_size &&
 260             __copy_from_user(fpstate + 4, (long *)&uc->uc_fpstate + 1,
 261                              context_size))
 262                 goto out;
 263         __asm__ volatile (".chip 68k/68881\n\t"
 264                           "frestore %0\n\t"
 265                           ".chip 68k" : : "m" (*fpstate));
 266         err = 0;
 267
 268 out:
 269         return err;
 270 }
 271
 272 #endif
 273
 274 static inline int
 275 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, void *fp,
 276                    int *pd0)
 277 {
 278         int formatvec;
 279         struct sigcontext context;
 280         int err = 0;
 281
 282         /* get previous context */
 283         if (copy_from_user(&context, usc, sizeof(context)))
 284                 goto badframe;
 285
 286         /* restore passed registers */
 287         regs->d1 = context.sc_d1;
 288         regs->a0 = context.sc_a0;
 289         regs->a1 = context.sc_a1;
 290         ((struct switch_stack *)regs - 1)->a5 = context.sc_a5;
 291         regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
 292         regs->pc = context.sc_pc;
 293         regs->orig_d0 = -1;             /* disable syscall checks */
 294         wrusp(context.sc_usp);
 295         formatvec = context.sc_formatvec;
 296         regs->format = formatvec >> 12;
 297         regs->vector = formatvec & 0xfff;
 298
 299 #ifdef CONFIG_FPU
 300         err = restore_fpu_state(&context);
 301 #endif
 302
 303         *pd0 = context.sc_d0;
 304         return err;
 305
 306 badframe:
 307         return 1;
 308 }
 309
 310 static inline int
 311 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
 312                     struct ucontext *uc, int *pd0)
 313 {
 314         int temp;
 315         greg_t *gregs = uc->uc_mcontext.gregs;
 316         unsigned long usp;
 317         int err;
 318
 319         err = __get_user(temp, &uc->uc_mcontext.version);
 320         if (temp != MCONTEXT_VERSION)
 321                 goto badframe;
 322         /* restore passed registers */
 323         err |= __get_user(regs->d0, &gregs[0]);
 324         err |= __get_user(regs->d1, &gregs[1]);
 325         err |= __get_user(regs->d2, &gregs[2]);
 326         err |= __get_user(regs->d3, &gregs[3]);
 327         err |= __get_user(regs->d4, &gregs[4]);
 328         err |= __get_user(regs->d5, &gregs[5]);
 329         err |= __get_user(sw->d6, &gregs[6]);
 330         err |= __get_user(sw->d7, &gregs[7]);
 331         err |= __get_user(regs->a0, &gregs[8]);
 332         err |= __get_user(regs->a1, &gregs[9]);
 333         err |= __get_user(regs->a2, &gregs[10]);
 334         err |= __get_user(sw->a3, &gregs[11]);
 335         err |= __get_user(sw->a4, &gregs[12]);
 336         err |= __get_user(sw->a5, &gregs[13]);
 337         err |= __get_user(sw->a6, &gregs[14]);
 338         err |= __get_user(usp, &gregs[15]);
 339         wrusp(usp);
 340         err |= __get_user(regs->pc, &gregs[16]);
 341         err |= __get_user(temp, &gregs[17]);
 342         regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
 343         regs->orig_d0 = -1;             /* disable syscall checks */
 344         regs->format = temp >> 12;
 345         regs->vector = temp & 0xfff;
 346
 347         if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
 348                 goto badframe;
 349
 350         *pd0 = regs->d0;
 351         return err;
 352
 353 badframe:
 354         return 1;
 355 }
 356
 357 asmlinkage int do_sigreturn(unsigned long __unused)
 358 {
 359         struct switch_stack *sw = (struct switch_stack *) &__unused;
 360         struct pt_regs *regs = (struct pt_regs *) (sw + 1);
 361         unsigned long usp = rdusp();
 362         struct sigframe *frame = (struct sigframe *)(usp - 4);
 363         sigset_t set;
 364         int d0;
 365
 366         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 367                 goto badframe;
 368         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
 369             (_NSIG_WORDS > 1 &&
 370              __copy_from_user(&set.sig[1], &frame->extramask,
 371                               sizeof(frame->extramask))))
 372                 goto badframe;
 373
 374         sigdelsetmask(&set, ~_BLOCKABLE);
 375         spin_lock_irq(&current->sighand->siglock);
 376         current->blocked = set;
 377         recalc_sigpending();
 378         spin_unlock_irq(&current->sighand->siglock);
 379
 380         if (restore_sigcontext(regs, &frame->sc, frame + 1, &d0))
 381                 goto badframe;
 382         return d0;
 383
 384 badframe:
 385         force_sig(SIGSEGV, current);
 386         return 0;
 387 }
 388
 389 asmlinkage int do_rt_sigreturn(unsigned long __unused)
 390 {
 391         struct switch_stack *sw = (struct switch_stack *) &__unused;
 392         struct pt_regs *regs = (struct pt_regs *) (sw + 1);
 393         unsigned long usp = rdusp();
 394         struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
 395         sigset_t set;
 396         int d0;
 397
 398         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 399                 goto badframe;
 400         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 401                 goto badframe;
 402
 403         sigdelsetmask(&set, ~_BLOCKABLE);
 404         spin_lock_irq(&current->sighand->siglock);
 405         current->blocked = set;
 406         recalc_sigpending();
 407         spin_unlock_irq(&current->sighand->siglock);
 408
 409         if (rt_restore_ucontext(regs, sw, &frame->uc, &d0))
 410                 goto badframe;
 411         return d0;
 412
 413 badframe:
 414         force_sig(SIGSEGV, current);
 415         return 0;
 416 }
 417
 418 #ifdef CONFIG_FPU
 419 /*
 420  * Set up a signal frame.
 421  */
 422
 423 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
 424 {
 425         if (FPU_IS_EMU) {
 426                 /* save registers */
 427                 memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
 428                 memcpy(sc->sc_fpregs, current->thread.fp, 24);
 429                 return;
 430         }
 431
 432         __asm__ volatile (".chip 68k/68881\n\t"
 433                           "fsave %0\n\t"
 434                           ".chip 68k"
 435                           : : "m" (*sc->sc_fpstate) : "memory");
 436
 437         if (sc->sc_fpstate[0]) {
 438                 fpu_version = sc->sc_fpstate[0];
 439                 __asm__ volatile (".chip 68k/68881\n\t"
 440                                   "fmovemx %/fp0-%/fp1,%0\n\t"
 441                                   "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
 442                                   ".chip 68k"
 443                                   : /* no outputs */
 444                                   : "m" (*sc->sc_fpregs),
 445                                     "m" (*sc->sc_fpcntl)
 446                                   : "memory");
 447         }
 448 }
 449
 450 static inline int rt_save_fpu_state(struct ucontext *uc, struct pt_regs *regs)
 451 {
 452         unsigned char fpstate[FPCONTEXT_SIZE];
 453         int context_size = 0;
 454         int err = 0;
 455
 456         if (FPU_IS_EMU) {
 457                 /* save fpu control register */
 458                 err |= copy_to_user(&uc->uc_mcontext.fpregs.f_pcr,
 459                                 current->thread.fpcntl, 12);
 460                 /* save all other fpu register */
 461                 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
 462                                 current->thread.fp, 96);
 463                 return err;
 464         }
 465
 466         __asm__ volatile (".chip 68k/68881\n\t"
 467                           "fsave %0\n\t"
 468                           ".chip 68k"
 469                           : : "m" (*fpstate) : "memory");
 470
 471         err |= __put_user(*(long *)fpstate, (long *)&uc->uc_fpstate);
 472         if (fpstate[0]) {
 473                 fpregset_t fpregs;
 474                 context_size = fpstate[1];
 475                 fpu_version = fpstate[0];
 476                 __asm__ volatile (".chip 68k/68881\n\t"
 477                                   "fmovemx %/fp0-%/fp7,%0\n\t"
 478                                   "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
 479                                   ".chip 68k"
 480                                   : /* no outputs */
 481                                   : "m" (*fpregs.f_fpregs),
 482                                     "m" (fpregs.f_pcr)
 483                                   : "memory");
 484                 err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
 485                                     sizeof(fpregs));
 486         }
 487         if (context_size)
 488                 err |= copy_to_user((long *)&uc->uc_fpstate + 1, fpstate + 4,
 489                                     context_size);
 490         return err;
 491 }
 492
 493 #endif
 494
 495 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
 496                              unsigned long mask)
 497 {
 498         sc->sc_mask = mask;
 499         sc->sc_usp = rdusp();
 500         sc->sc_d0 = regs->d0;
 501         sc->sc_d1 = regs->d1;
 502         sc->sc_a0 = regs->a0;
 503         sc->sc_a1 = regs->a1;
 504         sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
 505         sc->sc_sr = regs->sr;
 506         sc->sc_pc = regs->pc;
 507         sc->sc_formatvec = regs->format << 12 | regs->vector;
 508 #ifdef CONFIG_FPU
 509         save_fpu_state(sc, regs);
 510 #endif
 511 }
 512
 513 static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
 514 {
 515         struct switch_stack *sw = (struct switch_stack *)regs - 1;
 516         greg_t *gregs = uc->uc_mcontext.gregs;
 517         int err = 0;
 518
 519         err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
 520         err |= __put_user(regs->d0, &gregs[0]);
 521         err |= __put_user(regs->d1, &gregs[1]);
 522         err |= __put_user(regs->d2, &gregs[2]);
 523         err |= __put_user(regs->d3, &gregs[3]);
 524         err |= __put_user(regs->d4, &gregs[4]);
 525         err |= __put_user(regs->d5, &gregs[5]);
 526         err |= __put_user(sw->d6, &gregs[6]);
 527         err |= __put_user(sw->d7, &gregs[7]);
 528         err |= __put_user(regs->a0, &gregs[8]);
 529         err |= __put_user(regs->a1, &gregs[9]);
 530         err |= __put_user(regs->a2, &gregs[10]);
 531         err |= __put_user(sw->a3, &gregs[11]);
 532         err |= __put_user(sw->a4, &gregs[12]);
 533         err |= __put_user(sw->a5, &gregs[13]);
 534         err |= __put_user(sw->a6, &gregs[14]);
 535         err |= __put_user(rdusp(), &gregs[15]);
 536         err |= __put_user(regs->pc, &gregs[16]);
 537         err |= __put_user(regs->sr, &gregs[17]);
 538 #ifdef CONFIG_FPU
 539         err |= rt_save_fpu_state(uc, regs);
 540 #endif
 541         return err;
 542 }
 543
 544 static inline void *
 545 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 546 {
 547         unsigned long usp;
 548
 549         /* Default to using normal stack.  */
 550         usp = rdusp();
 551
 552         /* This is the X/Open sanctioned signal stack switching.  */
 553         if (ka->sa.sa_flags & SA_ONSTACK) {
 554                 if (!sas_ss_flags(usp))
 555                         usp = current->sas_ss_sp + current->sas_ss_size;
 556         }
 557         return (void *)((usp - frame_size) & -8UL);
 558 }
 559
 560 static void setup_frame (int sig, struct k_sigaction *ka,
 561                          sigset_t *set, struct pt_regs *regs)
 562 {
 563         struct sigframe *frame;
 564         struct sigcontext context;
 565         int err = 0;
 566
 567         frame = get_sigframe(ka, regs, sizeof(*frame));
 568
 569         err |= __put_user((current_thread_info()->exec_domain
 570                            && current_thread_info()->exec_domain->signal_invmap
 571                            && sig < 32
 572                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 573                            : sig),
 574                           &frame->sig);
 575
 576         err |= __put_user(regs->vector, &frame->code);
 577         err |= __put_user(&frame->sc, &frame->psc);
 578
 579         if (_NSIG_WORDS > 1)
 580                 err |= copy_to_user(frame->extramask, &set->sig[1],
 581                                     sizeof(frame->extramask));
 582
 583         setup_sigcontext(&context, regs, set->sig[0]);
 584         err |= copy_to_user (&frame->sc, &context, sizeof(context));
 585
 586         /* Set up to return from userspace.  */
 587         err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
 588
 589         if (err)
 590                 goto give_sigsegv;
 591
 592         /* Set up registers for signal handler */
 593         wrusp ((unsigned long) frame);
 594         regs->pc = (unsigned long) ka->sa.sa_handler;
 595         ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
 596         regs->format = 0x4; /*set format byte to make stack appear modulo 4
 597                                                 which it will be when doing the rte */
 598
 599 adjust_stack:
 600         /* Prepare to skip over the extra stuff in the exception frame.  */
 601         if (regs->stkadj) {
 602                 struct pt_regs *tregs =
 603                         (struct pt_regs *)((ulong)regs + regs->stkadj);
 604 #if defined(DEBUG)
 605                 printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
 606 #endif
 607                 /* This must be copied with decreasing addresses to
 608                    handle overlaps.  */
 609                 tregs->vector = 0;
 610                 tregs->format = 0;
 611                 tregs->pc = regs->pc;
 612                 tregs->sr = regs->sr;
 613         }
 614         return;
 615
 616 give_sigsegv:
 617         force_sigsegv(sig, current);
 618         goto adjust_stack;
 619 }
 620
 621 static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 622                             sigset_t *set, struct pt_regs *regs)
 623 {
 624         struct rt_sigframe *frame;
 625         int err = 0;
 626
 627         frame = get_sigframe(ka, regs, sizeof(*frame));
 628
 629         err |= __put_user((current_thread_info()->exec_domain
 630                            && current_thread_info()->exec_domain->signal_invmap
 631                            && sig < 32
 632                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 633                            : sig),
 634                           &frame->sig);
 635         err |= __put_user(&frame->info, &frame->pinfo);
 636         err |= __put_user(&frame->uc, &frame->puc);
 637         err |= copy_siginfo_to_user(&frame->info, info);
 638
 639         /* Create the ucontext.  */
 640         err |= __put_user(0, &frame->uc.uc_flags);
 641         err |= __put_user(0, &frame->uc.uc_link);
 642         err |= __put_user((void *)current->sas_ss_sp,
 643                           &frame->uc.uc_stack.ss_sp);
 644         err |= __put_user(sas_ss_flags(rdusp()),
 645                           &frame->uc.uc_stack.ss_flags);
 646         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 647         err |= rt_setup_ucontext(&frame->uc, regs);
 648         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
 649
 650         /* Set up to return from userspace.  */
 651         err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
 652
 653         if (err)
 654                 goto give_sigsegv;
 655
 656         /* Set up registers for signal handler */
 657         wrusp ((unsigned long) frame);
 658         regs->pc = (unsigned long) ka->sa.sa_handler;
 659         ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
 660         regs->format = 0x4; /*set format byte to make stack appear modulo 4
 661                                                 which it will be when doing the rte */
 662
 663 adjust_stack:
 664         /* Prepare to skip over the extra stuff in the exception frame.  */
 665         if (regs->stkadj) {
 666                 struct pt_regs *tregs =
 667                         (struct pt_regs *)((ulong)regs + regs->stkadj);
 668 #if defined(DEBUG)
 669                 printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
 670 #endif
 671                 /* This must be copied with decreasing addresses to
 672                    handle overlaps.  */
 673                 tregs->vector = 0;
 674                 tregs->format = 0;
 675                 tregs->pc = regs->pc;
 676                 tregs->sr = regs->sr;
 677         }
 678         return;
 679
 680 give_sigsegv:
 681         force_sigsegv(sig, current);
 682         goto adjust_stack;
 683 }
 684
 685 static inline void
 686 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
 687 {
 688         switch (regs->d0) {
 689         case -ERESTARTNOHAND:
 690                 if (!has_handler)
 691                         goto do_restart;
 692                 regs->d0 = -EINTR;
 693                 break;
 694
 695         case -ERESTARTSYS:
 696                 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
 697                         regs->d0 = -EINTR;
 698                         break;
 699                 }
 700         /* fallthrough */
 701         case -ERESTARTNOINTR:
 702         do_restart:
 703                 regs->d0 = regs->orig_d0;
 704                 regs->pc -= 2;
 705                 break;
 706         }
 707 }
 708
 709 /*
 710  * OK, we're invoking a handler
 711  */
 712 static void
 713 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
 714               sigset_t *oldset, struct pt_regs *regs)
 715 {
 716         /* are we from a system call? */
 717         if (regs->orig_d0 >= 0)
 718                 /* If so, check system call restarting.. */
 719                 handle_restart(regs, ka, 1);
 720
 721         /* set up the stack frame */
 722         if (ka->sa.sa_flags & SA_SIGINFO)
 723                 setup_rt_frame(sig, ka, info, oldset, regs);
 724         else
 725                 setup_frame(sig, ka, oldset, regs);
 726
 727         if (ka->sa.sa_flags & SA_ONESHOT)
 728                 ka->sa.sa_handler = SIG_DFL;
 729
 730         spin_lock_irq(&current->sighand->siglock);
 731         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 732         if (!(ka->sa.sa_flags & SA_NODEFER))
 733                 sigaddset(&current->blocked,sig);
 734         recalc_sigpending();
 735         spin_unlock_irq(&current->sighand->siglock);
 736 }
 737
 738 /*
 739  * Note that 'init' is a special process: it doesn't get signals it doesn't
 740  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 741  * mistake.
 742  */
 743 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
 744 {
 745         struct k_sigaction ka;
 746         siginfo_t info;
 747         int signr;
 748
 749         /*
 750          * We want the common case to go fast, which
 751          * is why we may in certain cases get here from
 752          * kernel mode. Just return without doing anything
 753          * if so.
 754          */
 755         if (!user_mode(regs))
 756                 return 1;
 757
 758         if (!oldset)
 759                 oldset = &current->blocked;
 760
 761         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 762         if (signr > 0) {
 763                 /* Whee!  Actually deliver the signal.  */
 764                 handle_signal(signr, &ka, &info, oldset, regs);
 765                 return 1;
 766         }
 767
 768         /* Did we come from a system call? */
 769         if (regs->orig_d0 >= 0) {
 770                 /* Restart the system call - no handlers present */
 771                 handle_restart(regs, NULL, 0);
 772         }
 773         return 0;
 774 }