arch/h8300/kernel/signal.c

   1 /*
   2  *  linux/arch/h8300/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  * uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp>
  13  *                and David McCullough <davidm@snapgear.com>
  14  *
  15  * Based on
  16  * Linux/m68k by Hamish Macdonald
  17  */
  18
  19 /*
  20  * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
  21  * Atari :-) Current limitation: Only one sigstack can be active at one time.
  22  * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
  23  * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
  24  * signal handlers!
  25  */
  26
  27 #include <linux/sched.h>
  28 #include <linux/mm.h>
  29 #include <linux/kernel.h>
  30 #include <linux/signal.h>
  31 #include <linux/syscalls.h>
  32 #include <linux/errno.h>
  33 #include <linux/wait.h>
  34 #include <linux/ptrace.h>
  35 #include <linux/unistd.h>
  36 #include <linux/stddef.h>
  37 #include <linux/highuid.h>
  38 #include <linux/personality.h>
  39 #include <linux/tty.h>
  40 #include <linux/binfmts.h>
  41 #include <linux/freezer.h>
  42
  43 #include <asm/setup.h>
  44 #include <asm/uaccess.h>
  45 #include <asm/pgtable.h>
  46 #include <asm/traps.h>
  47 #include <asm/ucontext.h>
  48
  49 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  50
  51 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
  52
  53 /*
  54  * Atomically swap in the new signal mask, and wait for a signal.
  55  */
  56 asmlinkage int do_sigsuspend(struct pt_regs *regs)
  57 {
  58         old_sigset_t mask = regs->er3;
  59         sigset_t saveset;
  60
  61         mask &= _BLOCKABLE;
  62         spin_lock_irq(&current->sighand->siglock);
  63         saveset = current->blocked;
  64         siginitset(&current->blocked, mask);
  65         recalc_sigpending();
  66         spin_unlock_irq(&current->sighand->siglock);
  67
  68         regs->er0 = -EINTR;
  69         while (1) {
  70                 current->state = TASK_INTERRUPTIBLE;
  71                 schedule();
  72                 if (do_signal(regs, &saveset))
  73                         return -EINTR;
  74         }
  75 }
  76
  77 asmlinkage int
  78 do_rt_sigsuspend(struct pt_regs *regs)
  79 {
  80         sigset_t *unewset = (sigset_t *)regs->er1;
  81         size_t sigsetsize = (size_t)regs->er2;
  82         sigset_t saveset, newset;
  83
  84         /* XXX: Don't preclude handling different sized sigset_t's.  */
  85         if (sigsetsize != sizeof(sigset_t))
  86                 return -EINVAL;
  87
  88         if (copy_from_user(&newset, unewset, sizeof(newset)))
  89                 return -EFAULT;
  90         sigdelsetmask(&newset, ~_BLOCKABLE);
  91
  92         spin_lock_irq(&current->sighand->siglock);
  93         saveset = current->blocked;
  94         current->blocked = newset;
  95         recalc_sigpending();
  96         spin_unlock_irq(&current->sighand->siglock);
  97
  98         regs->er0 = -EINTR;
  99         while (1) {
 100                 current->state = TASK_INTERRUPTIBLE;
 101                 schedule();
 102                 if (do_signal(regs, &saveset))
 103                         return -EINTR;
 104         }
 105 }
 106
 107 asmlinkage int
 108 sys_sigaction(int sig, const struct old_sigaction *act,
 109               struct old_sigaction *oact)
 110 {
 111         struct k_sigaction new_ka, old_ka;
 112         int ret;
 113
 114         if (act) {
 115                 old_sigset_t mask;
 116                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 117                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 118                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 119                         return -EFAULT;
 120                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 121                 __get_user(mask, &act->sa_mask);
 122                 siginitset(&new_ka.sa.sa_mask, mask);
 123         }
 124
 125         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 126
 127         if (!ret && oact) {
 128                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 129                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 130                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 131                         return -EFAULT;
 132                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 133                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 134         }
 135
 136         return ret;
 137 }
 138
 139 asmlinkage int
 140 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
 141 {
 142         return do_sigaltstack(uss, uoss, rdusp());
 143 }
 144
 145
 146 /*
 147  * Do a signal return; undo the signal stack.
 148  *
 149  * Keep the return code on the stack quadword aligned!
 150  * That makes the cache flush below easier.
 151  */
 152
 153 struct sigframe
 154 {
 155         long dummy_er0;
 156         long dummy_vector;
 157 #if defined(CONFIG_CPU_H8S)
 158         short dummy_exr;
 159 #endif
 160         long dummy_pc;
 161         char *pretcode;
 162         unsigned char retcode[8];
 163         unsigned long extramask[_NSIG_WORDS-1];
 164         struct sigcontext sc;
 165         int sig;
 166 } __attribute__((aligned(2),packed));
 167
 168 struct rt_sigframe
 169 {
 170         long dummy_er0;
 171         long dummy_vector;
 172 #if defined(CONFIG_CPU_H8S)
 173         short dummy_exr;
 174 #endif
 175         long dummy_pc;
 176         char *pretcode;
 177         struct siginfo *pinfo;
 178         void *puc;
 179         unsigned char retcode[8];
 180         struct siginfo info;
 181         struct ucontext uc;
 182         int sig;
 183 } __attribute__((aligned(2),packed));
 184
 185 static inline int
 186 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc,
 187                    int *pd0)
 188 {
 189         int err = 0;
 190         unsigned int ccr;
 191         unsigned int usp;
 192         unsigned int er0;
 193
 194         /* Always make any pending restarted system calls return -EINTR */
 195         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 196
 197 #define COPY(r) err |= __get_user(regs->r, &usc->sc_##r)    /* restore passed registers */
 198         COPY(er1);
 199         COPY(er2);
 200         COPY(er3);
 201         COPY(er5);
 202         COPY(pc);
 203         ccr = regs->ccr & 0x10;
 204         COPY(ccr);
 205 #undef COPY
 206         regs->ccr &= 0xef;
 207         regs->ccr |= ccr;
 208         regs->orig_er0 = -1;            /* disable syscall checks */
 209         err |= __get_user(usp, &usc->sc_usp);
 210         wrusp(usp);
 211
 212         err |= __get_user(er0, &usc->sc_er0);
 213         *pd0 = er0;
 214         return err;
 215 }
 216
 217 asmlinkage int do_sigreturn(unsigned long __unused,...)
 218 {
 219         struct pt_regs *regs = (struct pt_regs *) (&__unused - 1);
 220         unsigned long usp = rdusp();
 221         struct sigframe *frame = (struct sigframe *)(usp - 4);
 222         sigset_t set;
 223         int er0;
 224
 225         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 226                 goto badframe;
 227         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
 228             (_NSIG_WORDS > 1 &&
 229              __copy_from_user(&set.sig[1], &frame->extramask,
 230                               sizeof(frame->extramask))))
 231                 goto badframe;
 232
 233         sigdelsetmask(&set, ~_BLOCKABLE);
 234         spin_lock_irq(&current->sighand->siglock);
 235         current->blocked = set;
 236         recalc_sigpending();
 237         spin_unlock_irq(&current->sighand->siglock);
 238
 239         if (restore_sigcontext(regs, &frame->sc, &er0))
 240                 goto badframe;
 241         return er0;
 242
 243 badframe:
 244         force_sig(SIGSEGV, current);
 245         return 0;
 246 }
 247
 248 asmlinkage int do_rt_sigreturn(unsigned long __unused,...)
 249 {
 250         struct pt_regs *regs = (struct pt_regs *) &__unused;
 251         unsigned long usp = rdusp();
 252         struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
 253         sigset_t set;
 254         int er0;
 255
 256         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 257                 goto badframe;
 258         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 259                 goto badframe;
 260
 261         sigdelsetmask(&set, ~_BLOCKABLE);
 262         spin_unlock_irq(&current->sighand->siglock);
 263         current->blocked = set;
 264         recalc_sigpending();
 265         spin_lock_irq(&current->sighand->siglock);
 266
 267         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0))
 268                 goto badframe;
 269
 270         if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
 271                 goto badframe;
 272
 273         return er0;
 274
 275 badframe:
 276         force_sig(SIGSEGV, current);
 277         return 0;
 278 }
 279
 280 static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 281                              unsigned long mask)
 282 {
 283         int err = 0;
 284
 285         err |= __put_user(regs->er0, &sc->sc_er0);
 286         err |= __put_user(regs->er1, &sc->sc_er1);
 287         err |= __put_user(regs->er2, &sc->sc_er2);
 288         err |= __put_user(regs->er3, &sc->sc_er3);
 289         err |= __put_user(regs->er4, &sc->sc_er4);
 290         err |= __put_user(regs->er5, &sc->sc_er5);
 291         err |= __put_user(regs->er6, &sc->sc_er6);
 292         err |= __put_user(rdusp(),   &sc->sc_usp);
 293         err |= __put_user(regs->pc,  &sc->sc_pc);
 294         err |= __put_user(regs->ccr, &sc->sc_ccr);
 295         err |= __put_user(mask,      &sc->sc_mask);
 296
 297         return err;
 298 }
 299
 300 static inline void *
 301 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 302 {
 303         unsigned long usp;
 304
 305         /* Default to using normal stack.  */
 306         usp = rdusp();
 307
 308         /* This is the X/Open sanctioned signal stack switching.  */
 309         if (ka->sa.sa_flags & SA_ONSTACK) {
 310                 if (!sas_ss_flags(usp))
 311                         usp = current->sas_ss_sp + current->sas_ss_size;
 312         }
 313         return (void *)((usp - frame_size) & -8UL);
 314 }
 315
 316 static void setup_frame (int sig, struct k_sigaction *ka,
 317                          sigset_t *set, struct pt_regs *regs)
 318 {
 319         struct sigframe *frame;
 320         int err = 0;
 321         int usig;
 322         unsigned char *ret;
 323
 324         frame = get_sigframe(ka, regs, sizeof(*frame));
 325
 326         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 327                 goto give_sigsegv;
 328
 329         usig = current_thread_info()->exec_domain
 330                 && current_thread_info()->exec_domain->signal_invmap
 331                 && sig < 32
 332                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 333                 : sig;
 334
 335         err |= __put_user(usig, &frame->sig);
 336         if (err)
 337                 goto give_sigsegv;
 338
 339         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 340         if (err)
 341                 goto give_sigsegv;
 342
 343         if (_NSIG_WORDS > 1) {
 344                 err |= copy_to_user(frame->extramask, &set->sig[1],
 345                                     sizeof(frame->extramask));
 346                 if (err)
 347                         goto give_sigsegv;
 348         }
 349
 350         ret = frame->retcode;
 351         if (ka->sa.sa_flags & SA_RESTORER)
 352                 ret = (unsigned char *)(ka->sa.sa_restorer);
 353         else {
 354                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 355                 err != __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 356                                   (unsigned long *)(frame->retcode + 0));
 357                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 358         }
 359
 360         /* Set up to return from userspace.  */
 361         err |= __put_user(ret, &frame->pretcode);
 362
 363         if (err)
 364                 goto give_sigsegv;
 365
 366         /* Set up registers for signal handler */
 367         wrusp ((unsigned long) frame);
 368         regs->pc = (unsigned long) ka->sa.sa_handler;
 369         regs->er0 = (current_thread_info()->exec_domain
 370                            && current_thread_info()->exec_domain->signal_invmap
 371                            && sig < 32
 372                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 373                           : sig);
 374         regs->er1 = (unsigned long)&(frame->sc);
 375         regs->er5 = current->mm->start_data;    /* GOT base */
 376
 377         return;
 378
 379 give_sigsegv:
 380         force_sigsegv(sig, current);
 381 }
 382
 383 static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 384                             sigset_t *set, struct pt_regs *regs)
 385 {
 386         struct rt_sigframe *frame;
 387         int err = 0;
 388         int usig;
 389         unsigned char *ret;
 390
 391         frame = get_sigframe(ka, regs, sizeof(*frame));
 392
 393         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 394                 goto give_sigsegv;
 395
 396         usig = current_thread_info()->exec_domain
 397                 && current_thread_info()->exec_domain->signal_invmap
 398                 && sig < 32
 399                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 400                 : sig;
 401
 402         err |= __put_user(usig, &frame->sig);
 403         if (err)
 404                 goto give_sigsegv;
 405
 406         err |= __put_user(&frame->info, &frame->pinfo);
 407         err |= __put_user(&frame->uc, &frame->puc);
 408         err |= copy_siginfo_to_user(&frame->info, info);
 409         if (err)
 410                 goto give_sigsegv;
 411
 412         /* Create the ucontext.  */
 413         err |= __put_user(0, &frame->uc.uc_flags);
 414         err |= __put_user(0, &frame->uc.uc_link);
 415         err |= __put_user((void *)current->sas_ss_sp,
 416                           &frame->uc.uc_stack.ss_sp);
 417         err |= __put_user(sas_ss_flags(rdusp()),
 418                           &frame->uc.uc_stack.ss_flags);
 419         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 420         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 421         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
 422         if (err)
 423                 goto give_sigsegv;
 424
 425         /* Set up to return from userspace.  */
 426         ret = frame->retcode;
 427         if (ka->sa.sa_flags & SA_RESTORER)
 428                 ret = (unsigned char *)(ka->sa.sa_restorer);
 429         else {
 430                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 431                 err != __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 432                                   (unsigned long *)(frame->retcode + 0));
 433                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 434         }
 435         err |= __put_user(ret, &frame->pretcode);
 436
 437         if (err)
 438                 goto give_sigsegv;
 439
 440         /* Set up registers for signal handler */
 441         wrusp ((unsigned long) frame);
 442         regs->pc  = (unsigned long) ka->sa.sa_handler;
 443         regs->er0 = (current_thread_info()->exec_domain
 444                      && current_thread_info()->exec_domain->signal_invmap
 445                      && sig < 32
 446                      ? current_thread_info()->exec_domain->signal_invmap[sig]
 447                      : sig);
 448         regs->er1 = (unsigned long)&(frame->info);
 449         regs->er2 = (unsigned long)&frame->uc;
 450         regs->er5 = current->mm->start_data;    /* GOT base */
 451
 452         return;
 453
 454 give_sigsegv:
 455         force_sigsegv(sig, current);
 456 }
 457
 458 /*
 459  * OK, we're invoking a handler
 460  */
 461 static void
 462 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 463               sigset_t *oldset, struct pt_regs * regs)
 464 {
 465         /* are we from a system call? */
 466         if (regs->orig_er0 >= 0) {
 467                 switch (regs->er0) {
 468                         case -ERESTART_RESTARTBLOCK:
 469                         case -ERESTARTNOHAND:
 470                                 regs->er0 = -EINTR;
 471                                 break;
 472
 473                         case -ERESTARTSYS:
 474                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 475                                         regs->er0 = -EINTR;
 476                                         break;
 477                                 }
 478                         /* fallthrough */
 479                         case -ERESTARTNOINTR:
 480                                 regs->er0 = regs->orig_er0;
 481                                 regs->pc -= 2;
 482                 }
 483         }
 484
 485         /* set up the stack frame */
 486         if (ka->sa.sa_flags & SA_SIGINFO)
 487                 setup_rt_frame(sig, ka, info, oldset, regs);
 488         else
 489                 setup_frame(sig, ka, oldset, regs);
 490
 491         spin_lock_irq(&current->sighand->siglock);
 492         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 493         if (!(ka->sa.sa_flags & SA_NODEFER))
 494                 sigaddset(&current->blocked,sig);
 495         recalc_sigpending();
 496         spin_unlock_irq(&current->sighand->siglock);
 497 }
 498
 499 /*
 500  * Note that 'init' is a special process: it doesn't get signals it doesn't
 501  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 502  * mistake.
 503  */
 504 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset)
 505 {
 506         siginfo_t info;
 507         int signr;
 508         struct k_sigaction ka;
 509
 510         /*
 511          * We want the common case to go fast, which
 512          * is why we may in certain cases get here from
 513          * kernel mode. Just return without doing anything
 514          * if so.
 515          */
 516         if ((regs->ccr & 0x10))
 517                 return 1;
 518
 519         if (try_to_freeze())
 520                 goto no_signal;
 521
 522         current->thread.esp0 = (unsigned long) regs;
 523
 524         if (!oldset)
 525                 oldset = &current->blocked;
 526
 527         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 528         if (signr > 0) {
 529                 /* Whee!  Actually deliver the signal.  */
 530                 handle_signal(signr, &info, &ka, oldset, regs);
 531                 return 1;
 532         }
 533  no_signal:
 534         /* Did we come from a system call? */
 535         if (regs->orig_er0 >= 0) {
 536                 /* Restart the system call - no handlers present */
 537                 if (regs->er0 == -ERESTARTNOHAND ||
 538                     regs->er0 == -ERESTARTSYS ||
 539                     regs->er0 == -ERESTARTNOINTR) {
 540                         regs->er0 = regs->orig_er0;
 541                         regs->pc -= 2;
 542                 }
 543                 if (regs->er0 == -ERESTART_RESTARTBLOCK){
 544                         regs->er0 = __NR_restart_syscall;
 545                         regs->pc -= 2;
 546                 }
 547         }
 548         return 0;
 549 }