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 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
  55
  56 /*
  57  * Atomically swap in the new signal mask, and wait for a signal.
  58  */
  59 asmlinkage int do_sigsuspend(struct pt_regs *regs)
  60 {
  61         old_sigset_t mask = regs->d3;
  62         sigset_t saveset;
  63
  64         mask &= _BLOCKABLE;
  65         spin_lock_irq(&current->sighand->siglock);
  66         saveset = current->blocked;
  67         siginitset(&current->blocked, mask);
  68         recalc_sigpending();
  69         spin_unlock_irq(&current->sighand->siglock);
  70
  71         regs->d0 = -EINTR;
  72         while (1) {
  73                 current->state = TASK_INTERRUPTIBLE;
  74                 schedule();
  75                 if (do_signal(&saveset, regs))
  76                         return -EINTR;
  77         }
  78 }
  79
  80 asmlinkage int
  81 do_rt_sigsuspend(struct pt_regs *regs)
  82 {
  83         sigset_t *unewset = (sigset_t *)regs->d1;
  84         size_t sigsetsize = (size_t)regs->d2;
  85         sigset_t saveset, newset;
  86
  87         /* XXX: Don't preclude handling different sized sigset_t's.  */
  88         if (sigsetsize != sizeof(sigset_t))
  89                 return -EINVAL;
  90
  91         if (copy_from_user(&newset, unewset, sizeof(newset)))
  92                 return -EFAULT;
  93         sigdelsetmask(&newset, ~_BLOCKABLE);
  94
  95         spin_lock_irq(&current->sighand->siglock);
  96         saveset = current->blocked;
  97         current->blocked = newset;
  98         recalc_sigpending();
  99         spin_unlock_irq(&current->sighand->siglock);
 100
 101         regs->d0 = -EINTR;
 102         while (1) {
 103                 current->state = TASK_INTERRUPTIBLE;
 104                 schedule();
 105                 if (do_signal(&saveset, regs))
 106                         return -EINTR;
 107         }
 108 }
 109
 110 asmlinkage int
 111 sys_sigaction(int sig, const struct old_sigaction *act,
 112               struct old_sigaction *oact)
 113 {
 114         struct k_sigaction new_ka, old_ka;
 115         int ret;
 116
 117         if (act) {
 118                 old_sigset_t mask;
 119                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 120                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 121                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 122                         return -EFAULT;
 123                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 124                 __get_user(mask, &act->sa_mask);
 125                 siginitset(&new_ka.sa.sa_mask, mask);
 126         }
 127
 128         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 129
 130         if (!ret && oact) {
 131                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 132                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 133                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 134                         return -EFAULT;
 135                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 136                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 137         }
 138
 139         return ret;
 140 }
 141
 142 asmlinkage int
 143 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
 144 {
 145         return do_sigaltstack(uss, uoss, rdusp());
 146 }
 147
 148
 149 /*
 150  * Do a signal return; undo the signal stack.
 151  *
 152  * Keep the return code on the stack quadword aligned!
 153  * That makes the cache flush below easier.
 154  */
 155
 156 struct sigframe
 157 {
 158         char *pretcode;
 159         int sig;
 160         int code;
 161         struct sigcontext *psc;
 162         char retcode[8];
 163         unsigned long extramask[_NSIG_WORDS-1];
 164         struct sigcontext sc;
 165 };
 166
 167 struct rt_sigframe
 168 {
 169         char *pretcode;
 170         int sig;
 171         struct siginfo *pinfo;
 172         void *puc;
 173         char retcode[8];
 174         struct siginfo info;
 175         struct ucontext uc;
 176 };
 177
 178 #ifdef CONFIG_FPU
 179
 180 static unsigned char fpu_version = 0;   /* version number of fpu, set by setup_frame */
 181
 182 static inline int restore_fpu_state(struct sigcontext *sc)
 183 {
 184         int err = 1;
 185
 186         if (FPU_IS_EMU) {
 187             /* restore registers */
 188             memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
 189             memcpy(current->thread.fp, sc->sc_fpregs, 24);
 190             return 0;
 191         }
 192
 193         if (sc->sc_fpstate[0]) {
 194             /* Verify the frame format.  */
 195             if (sc->sc_fpstate[0] != fpu_version)
 196                 goto out;
 197
 198             __asm__ volatile (".chip 68k/68881\n\t"
 199                               "fmovemx %0,%/fp0-%/fp1\n\t"
 200                               "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t"
 201                               ".chip 68k"
 202                               : /* no outputs */
 203                               : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl));
 204         }
 205         __asm__ volatile (".chip 68k/68881\n\t"
 206                           "frestore %0\n\t"
 207                           ".chip 68k" : : "m" (*sc->sc_fpstate));
 208         err = 0;
 209
 210 out:
 211         return err;
 212 }
 213
 214 #define FPCONTEXT_SIZE  216
 215 #define uc_fpstate      uc_filler[0]
 216 #define uc_formatvec    uc_filler[FPCONTEXT_SIZE/4]
 217 #define uc_extra        uc_filler[FPCONTEXT_SIZE/4+1]
 218
 219 static inline int rt_restore_fpu_state(struct ucontext *uc)
 220 {
 221         unsigned char fpstate[FPCONTEXT_SIZE];
 222         int context_size = 0;
 223         fpregset_t fpregs;
 224         int err = 1;
 225
 226         if (FPU_IS_EMU) {
 227                 /* restore fpu control register */
 228                 if (__copy_from_user(current->thread.fpcntl,
 229                                 &uc->uc_mcontext.fpregs.f_pcr, 12))
 230                         goto out;
 231                 /* restore all other fpu register */
 232                 if (__copy_from_user(current->thread.fp,
 233                                 uc->uc_mcontext.fpregs.f_fpregs, 96))
 234                         goto out;
 235                 return 0;
 236         }
 237
 238         if (__get_user(*(long *)fpstate, (long *)&uc->uc_fpstate))
 239                 goto out;
 240         if (fpstate[0]) {
 241                 context_size = fpstate[1];
 242
 243                 /* Verify the frame format.  */
 244                 if (fpstate[0] != fpu_version)
 245                         goto out;
 246                 if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
 247                      sizeof(fpregs)))
 248                         goto out;
 249                 __asm__ volatile (".chip 68k/68881\n\t"
 250                                   "fmovemx %0,%/fp0-%/fp7\n\t"
 251                                   "fmoveml %1,%/fpcr/%/fpsr/%/fpiar\n\t"
 252                                   ".chip 68k"
 253                                   : /* no outputs */
 254                                   : "m" (*fpregs.f_fpregs),
 255                                     "m" (fpregs.f_pcr));
 256         }
 257         if (context_size &&
 258             __copy_from_user(fpstate + 4, (long *)&uc->uc_fpstate + 1,
 259                              context_size))
 260                 goto out;
 261         __asm__ volatile (".chip 68k/68881\n\t"
 262                           "frestore %0\n\t"
 263                           ".chip 68k" : : "m" (*fpstate));
 264         err = 0;
 265
 266 out:
 267         return err;
 268 }
 269
 270 #endif
 271
 272 static inline int
 273 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc, void *fp,
 274                    int *pd0)
 275 {
 276         int formatvec;
 277         struct sigcontext context;
 278         int err = 0;
 279
 280         /* get previous context */
 281         if (copy_from_user(&context, usc, sizeof(context)))
 282                 goto badframe;
 283
 284         /* restore passed registers */
 285         regs->d1 = context.sc_d1;
 286         regs->a0 = context.sc_a0;
 287         regs->a1 = context.sc_a1;
 288         ((struct switch_stack *)regs - 1)->a5 = context.sc_a5;
 289         regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
 290         regs->pc = context.sc_pc;
 291         regs->orig_d0 = -1;             /* disable syscall checks */
 292         wrusp(context.sc_usp);
 293         formatvec = context.sc_formatvec;
 294         regs->format = formatvec >> 12;
 295         regs->vector = formatvec & 0xfff;
 296
 297 #ifdef CONFIG_FPU
 298         err = restore_fpu_state(&context);
 299 #endif
 300
 301         *pd0 = context.sc_d0;
 302         return err;
 303
 304 badframe:
 305         return 1;
 306 }
 307
 308 static inline int
 309 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
 310                     struct ucontext *uc, int *pd0)
 311 {
 312         int temp;
 313         greg_t *gregs = uc->uc_mcontext.gregs;
 314         unsigned long usp;
 315         int err;
 316
 317         err = __get_user(temp, &uc->uc_mcontext.version);
 318         if (temp != MCONTEXT_VERSION)
 319                 goto badframe;
 320         /* restore passed registers */
 321         err |= __get_user(regs->d0, &gregs[0]);
 322         err |= __get_user(regs->d1, &gregs[1]);
 323         err |= __get_user(regs->d2, &gregs[2]);
 324         err |= __get_user(regs->d3, &gregs[3]);
 325         err |= __get_user(regs->d4, &gregs[4]);
 326         err |= __get_user(regs->d5, &gregs[5]);
 327         err |= __get_user(sw->d6, &gregs[6]);
 328         err |= __get_user(sw->d7, &gregs[7]);
 329         err |= __get_user(regs->a0, &gregs[8]);
 330         err |= __get_user(regs->a1, &gregs[9]);
 331         err |= __get_user(regs->a2, &gregs[10]);
 332         err |= __get_user(sw->a3, &gregs[11]);
 333         err |= __get_user(sw->a4, &gregs[12]);
 334         err |= __get_user(sw->a5, &gregs[13]);
 335         err |= __get_user(sw->a6, &gregs[14]);
 336         err |= __get_user(usp, &gregs[15]);
 337         wrusp(usp);
 338         err |= __get_user(regs->pc, &gregs[16]);
 339         err |= __get_user(temp, &gregs[17]);
 340         regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
 341         regs->orig_d0 = -1;             /* disable syscall checks */
 342         regs->format = temp >> 12;
 343         regs->vector = temp & 0xfff;
 344
 345         if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
 346                 goto badframe;
 347
 348         *pd0 = regs->d0;
 349         return err;
 350
 351 badframe:
 352         return 1;
 353 }
 354
 355 asmlinkage int do_sigreturn(unsigned long __unused)
 356 {
 357         struct switch_stack *sw = (struct switch_stack *) &__unused;
 358         struct pt_regs *regs = (struct pt_regs *) (sw + 1);
 359         unsigned long usp = rdusp();
 360         struct sigframe *frame = (struct sigframe *)(usp - 4);
 361         sigset_t set;
 362         int d0;
 363
 364         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 365                 goto badframe;
 366         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
 367             (_NSIG_WORDS > 1 &&
 368              __copy_from_user(&set.sig[1], &frame->extramask,
 369                               sizeof(frame->extramask))))
 370                 goto badframe;
 371
 372         sigdelsetmask(&set, ~_BLOCKABLE);
 373         spin_lock_irq(&current->sighand->siglock);
 374         current->blocked = set;
 375         recalc_sigpending();
 376         spin_unlock_irq(&current->sighand->siglock);
 377
 378         if (restore_sigcontext(regs, &frame->sc, frame + 1, &d0))
 379                 goto badframe;
 380         return d0;
 381
 382 badframe:
 383         force_sig(SIGSEGV, current);
 384         return 0;
 385 }
 386
 387 asmlinkage int do_rt_sigreturn(unsigned long __unused)
 388 {
 389         struct switch_stack *sw = (struct switch_stack *) &__unused;
 390         struct pt_regs *regs = (struct pt_regs *) (sw + 1);
 391         unsigned long usp = rdusp();
 392         struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
 393         sigset_t set;
 394         int d0;
 395
 396         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 397                 goto badframe;
 398         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 399                 goto badframe;
 400
 401         sigdelsetmask(&set, ~_BLOCKABLE);
 402         spin_lock_irq(&current->sighand->siglock);
 403         current->blocked = set;
 404         recalc_sigpending();
 405         spin_unlock_irq(&current->sighand->siglock);
 406
 407         if (rt_restore_ucontext(regs, sw, &frame->uc, &d0))
 408                 goto badframe;
 409         return d0;
 410
 411 badframe:
 412         force_sig(SIGSEGV, current);
 413         return 0;
 414 }
 415
 416 #ifdef CONFIG_FPU
 417 /*
 418  * Set up a signal frame.
 419  */
 420
 421 static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
 422 {
 423         if (FPU_IS_EMU) {
 424                 /* save registers */
 425                 memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
 426                 memcpy(sc->sc_fpregs, current->thread.fp, 24);
 427                 return;
 428         }
 429
 430         __asm__ volatile (".chip 68k/68881\n\t"
 431                           "fsave %0\n\t"
 432                           ".chip 68k"
 433                           : : "m" (*sc->sc_fpstate) : "memory");
 434
 435         if (sc->sc_fpstate[0]) {
 436                 fpu_version = sc->sc_fpstate[0];
 437                 __asm__ volatile (".chip 68k/68881\n\t"
 438                                   "fmovemx %/fp0-%/fp1,%0\n\t"
 439                                   "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
 440                                   ".chip 68k"
 441                                   : /* no outputs */
 442                                   : "m" (*sc->sc_fpregs),
 443                                     "m" (*sc->sc_fpcntl)
 444                                   : "memory");
 445         }
 446 }
 447
 448 static inline int rt_save_fpu_state(struct ucontext *uc, struct pt_regs *regs)
 449 {
 450         unsigned char fpstate[FPCONTEXT_SIZE];
 451         int context_size = 0;
 452         int err = 0;
 453
 454         if (FPU_IS_EMU) {
 455                 /* save fpu control register */
 456                 err |= copy_to_user(&uc->uc_mcontext.fpregs.f_pcr,
 457                                 current->thread.fpcntl, 12);
 458                 /* save all other fpu register */
 459                 err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
 460                                 current->thread.fp, 96);
 461                 return err;
 462         }
 463
 464         __asm__ volatile (".chip 68k/68881\n\t"
 465                           "fsave %0\n\t"
 466                           ".chip 68k"
 467                           : : "m" (*fpstate) : "memory");
 468
 469         err |= __put_user(*(long *)fpstate, (long *)&uc->uc_fpstate);
 470         if (fpstate[0]) {
 471                 fpregset_t fpregs;
 472                 context_size = fpstate[1];
 473                 fpu_version = fpstate[0];
 474                 __asm__ volatile (".chip 68k/68881\n\t"
 475                                   "fmovemx %/fp0-%/fp7,%0\n\t"
 476                                   "fmoveml %/fpcr/%/fpsr/%/fpiar,%1\n\t"
 477                                   ".chip 68k"
 478                                   : /* no outputs */
 479                                   : "m" (*fpregs.f_fpregs),
 480                                     "m" (fpregs.f_pcr)
 481                                   : "memory");
 482                 err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
 483                                     sizeof(fpregs));
 484         }
 485         if (context_size)
 486                 err |= copy_to_user((long *)&uc->uc_fpstate + 1, fpstate + 4,
 487                                     context_size);
 488         return err;
 489 }
 490
 491 #endif
 492
 493 static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
 494                              unsigned long mask)
 495 {
 496         sc->sc_mask = mask;
 497         sc->sc_usp = rdusp();
 498         sc->sc_d0 = regs->d0;
 499         sc->sc_d1 = regs->d1;
 500         sc->sc_a0 = regs->a0;
 501         sc->sc_a1 = regs->a1;
 502         sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
 503         sc->sc_sr = regs->sr;
 504         sc->sc_pc = regs->pc;
 505         sc->sc_formatvec = regs->format << 12 | regs->vector;
 506 #ifdef CONFIG_FPU
 507         save_fpu_state(sc, regs);
 508 #endif
 509 }
 510
 511 static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs)
 512 {
 513         struct switch_stack *sw = (struct switch_stack *)regs - 1;
 514         greg_t *gregs = uc->uc_mcontext.gregs;
 515         int err = 0;
 516
 517         err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
 518         err |= __put_user(regs->d0, &gregs[0]);
 519         err |= __put_user(regs->d1, &gregs[1]);
 520         err |= __put_user(regs->d2, &gregs[2]);
 521         err |= __put_user(regs->d3, &gregs[3]);
 522         err |= __put_user(regs->d4, &gregs[4]);
 523         err |= __put_user(regs->d5, &gregs[5]);
 524         err |= __put_user(sw->d6, &gregs[6]);
 525         err |= __put_user(sw->d7, &gregs[7]);
 526         err |= __put_user(regs->a0, &gregs[8]);
 527         err |= __put_user(regs->a1, &gregs[9]);
 528         err |= __put_user(regs->a2, &gregs[10]);
 529         err |= __put_user(sw->a3, &gregs[11]);
 530         err |= __put_user(sw->a4, &gregs[12]);
 531         err |= __put_user(sw->a5, &gregs[13]);
 532         err |= __put_user(sw->a6, &gregs[14]);
 533         err |= __put_user(rdusp(), &gregs[15]);
 534         err |= __put_user(regs->pc, &gregs[16]);
 535         err |= __put_user(regs->sr, &gregs[17]);
 536 #ifdef CONFIG_FPU
 537         err |= rt_save_fpu_state(uc, regs);
 538 #endif
 539         return err;
 540 }
 541
 542 static inline void push_cache (unsigned long vaddr)
 543 {
 544 }
 545
 546 static inline void *
 547 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 548 {
 549         unsigned long usp;
 550
 551         /* Default to using normal stack.  */
 552         usp = rdusp();
 553
 554         /* This is the X/Open sanctioned signal stack switching.  */
 555         if (ka->sa.sa_flags & SA_ONSTACK) {
 556                 if (!sas_ss_flags(usp))
 557                         usp = current->sas_ss_sp + current->sas_ss_size;
 558         }
 559         return (void *)((usp - frame_size) & -8UL);
 560 }
 561
 562 static void setup_frame (int sig, struct k_sigaction *ka,
 563                          sigset_t *set, struct pt_regs *regs)
 564 {
 565         struct sigframe *frame;
 566         struct sigcontext context;
 567         int err = 0;
 568
 569         frame = get_sigframe(ka, regs, sizeof(*frame));
 570
 571         err |= __put_user((current_thread_info()->exec_domain
 572                            && current_thread_info()->exec_domain->signal_invmap
 573                            && sig < 32
 574                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 575                            : sig),
 576                           &frame->sig);
 577
 578         err |= __put_user(regs->vector, &frame->code);
 579         err |= __put_user(&frame->sc, &frame->psc);
 580
 581         if (_NSIG_WORDS > 1)
 582                 err |= copy_to_user(frame->extramask, &set->sig[1],
 583                                     sizeof(frame->extramask));
 584
 585         setup_sigcontext(&context, regs, set->sig[0]);
 586         err |= copy_to_user (&frame->sc, &context, sizeof(context));
 587
 588         /* Set up to return from userspace.  */
 589         err |= __put_user(frame->retcode, &frame->pretcode);
 590         /* moveq #,d0; trap #0 */
 591         err |= __put_user(0x70004e40 + (__NR_sigreturn << 16),
 592                           (long *)(frame->retcode));
 593
 594         if (err)
 595                 goto give_sigsegv;
 596
 597         push_cache ((unsigned long) &frame->retcode);
 598
 599         /* Set up registers for signal handler */
 600         wrusp ((unsigned long) frame);
 601         regs->pc = (unsigned long) ka->sa.sa_handler;
 602         ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
 603         regs->format = 0x4; /*set format byte to make stack appear modulo 4
 604                                                 which it will be when doing the rte */
 605
 606 adjust_stack:
 607         /* Prepare to skip over the extra stuff in the exception frame.  */
 608         if (regs->stkadj) {
 609                 struct pt_regs *tregs =
 610                         (struct pt_regs *)((ulong)regs + regs->stkadj);
 611 #if defined(DEBUG)
 612                 printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
 613 #endif
 614                 /* This must be copied with decreasing addresses to
 615                    handle overlaps.  */
 616                 tregs->vector = 0;
 617                 tregs->format = 0;
 618                 tregs->pc = regs->pc;
 619                 tregs->sr = regs->sr;
 620         }
 621         return;
 622
 623 give_sigsegv:
 624         force_sigsegv(sig, current);
 625         goto adjust_stack;
 626 }
 627
 628 static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 629                             sigset_t *set, struct pt_regs *regs)
 630 {
 631         struct rt_sigframe *frame;
 632         int err = 0;
 633
 634         frame = get_sigframe(ka, regs, sizeof(*frame));
 635
 636         err |= __put_user((current_thread_info()->exec_domain
 637                            && current_thread_info()->exec_domain->signal_invmap
 638                            && sig < 32
 639                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 640                            : sig),
 641                           &frame->sig);
 642         err |= __put_user(&frame->info, &frame->pinfo);
 643         err |= __put_user(&frame->uc, &frame->puc);
 644         err |= copy_siginfo_to_user(&frame->info, info);
 645
 646         /* Create the ucontext.  */
 647         err |= __put_user(0, &frame->uc.uc_flags);
 648         err |= __put_user(0, &frame->uc.uc_link);
 649         err |= __put_user((void *)current->sas_ss_sp,
 650                           &frame->uc.uc_stack.ss_sp);
 651         err |= __put_user(sas_ss_flags(rdusp()),
 652                           &frame->uc.uc_stack.ss_flags);
 653         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 654         err |= rt_setup_ucontext(&frame->uc, regs);
 655         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
 656
 657         /* Set up to return from userspace.  */
 658         err |= __put_user(frame->retcode, &frame->pretcode);
 659         /* moveq #,d0; notb d0; trap #0 */
 660         err |= __put_user(0x70004600 + ((__NR_rt_sigreturn ^ 0xff) << 16),
 661                           (long *)(frame->retcode + 0));
 662         err |= __put_user(0x4e40, (short *)(frame->retcode + 4));
 663
 664         if (err)
 665                 goto give_sigsegv;
 666
 667         push_cache ((unsigned long) &frame->retcode);
 668
 669         /* Set up registers for signal handler */
 670         wrusp ((unsigned long) frame);
 671         regs->pc = (unsigned long) ka->sa.sa_handler;
 672         ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
 673         regs->format = 0x4; /*set format byte to make stack appear modulo 4
 674                                                 which it will be when doing the rte */
 675
 676 adjust_stack:
 677         /* Prepare to skip over the extra stuff in the exception frame.  */
 678         if (regs->stkadj) {
 679                 struct pt_regs *tregs =
 680                         (struct pt_regs *)((ulong)regs + regs->stkadj);
 681 #if defined(DEBUG)
 682                 printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
 683 #endif
 684                 /* This must be copied with decreasing addresses to
 685                    handle overlaps.  */
 686                 tregs->vector = 0;
 687                 tregs->format = 0;
 688                 tregs->pc = regs->pc;
 689                 tregs->sr = regs->sr;
 690         }
 691         return;
 692
 693 give_sigsegv:
 694         force_sigsegv(sig, current);
 695         goto adjust_stack;
 696 }
 697
 698 static inline void
 699 handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
 700 {
 701         switch (regs->d0) {
 702         case -ERESTARTNOHAND:
 703                 if (!has_handler)
 704                         goto do_restart;
 705                 regs->d0 = -EINTR;
 706                 break;
 707
 708         case -ERESTARTSYS:
 709                 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
 710                         regs->d0 = -EINTR;
 711                         break;
 712                 }
 713         /* fallthrough */
 714         case -ERESTARTNOINTR:
 715         do_restart:
 716                 regs->d0 = regs->orig_d0;
 717                 regs->pc -= 2;
 718                 break;
 719         }
 720 }
 721
 722 /*
 723  * OK, we're invoking a handler
 724  */
 725 static void
 726 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
 727               sigset_t *oldset, struct pt_regs *regs)
 728 {
 729         /* are we from a system call? */
 730         if (regs->orig_d0 >= 0)
 731                 /* If so, check system call restarting.. */
 732                 handle_restart(regs, ka, 1);
 733
 734         /* set up the stack frame */
 735         if (ka->sa.sa_flags & SA_SIGINFO)
 736                 setup_rt_frame(sig, ka, info, oldset, regs);
 737         else
 738                 setup_frame(sig, ka, oldset, regs);
 739
 740         if (ka->sa.sa_flags & SA_ONESHOT)
 741                 ka->sa.sa_handler = SIG_DFL;
 742
 743         spin_lock_irq(&current->sighand->siglock);
 744         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 745         if (!(ka->sa.sa_flags & SA_NODEFER))
 746                 sigaddset(&current->blocked,sig);
 747         recalc_sigpending();
 748         spin_unlock_irq(&current->sighand->siglock);
 749 }
 750
 751 /*
 752  * Note that 'init' is a special process: it doesn't get signals it doesn't
 753  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 754  * mistake.
 755  */
 756 asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
 757 {
 758         struct k_sigaction ka;
 759         siginfo_t info;
 760         int signr;
 761
 762         /*
 763          * We want the common case to go fast, which
 764          * is why we may in certain cases get here from
 765          * kernel mode. Just return without doing anything
 766          * if so.
 767          */
 768         if (!user_mode(regs))
 769                 return 1;
 770
 771         if (!oldset)
 772                 oldset = &current->blocked;
 773
 774         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 775         if (signr > 0) {
 776                 /* Whee!  Actually deliver the signal.  */
 777                 handle_signal(signr, &ka, &info, oldset, regs);
 778                 return 1;
 779         }
 780
 781         /* Did we come from a system call? */
 782         if (regs->orig_d0 >= 0) {
 783                 /* Restart the system call - no handlers present */
 784                 handle_restart(regs, NULL, 0);
 785         }
 786         return 0;
 787 }