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 #include <linux/tracehook.h>
  43
  44 #include <asm/setup.h>
  45 #include <asm/uaccess.h>
  46 #include <asm/pgtable.h>
  47 #include <asm/traps.h>
  48 #include <asm/ucontext.h>
  49
  50 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  51
  52 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
  53
  54 /*
  55  * Atomically swap in the new signal mask, and wait for a signal.
  56  */
  57 asmlinkage int do_sigsuspend(struct pt_regs *regs)
  58 {
  59         old_sigset_t mask = regs->er3;
  60         sigset_t saveset;
  61
  62         mask &= _BLOCKABLE;
  63         spin_lock_irq(&current->sighand->siglock);
  64         saveset = current->blocked;
  65         siginitset(&current->blocked, mask);
  66         recalc_sigpending();
  67         spin_unlock_irq(&current->sighand->siglock);
  68
  69         regs->er0 = -EINTR;
  70         while (1) {
  71                 current->state = TASK_INTERRUPTIBLE;
  72                 schedule();
  73                 if (do_signal(regs, &saveset))
  74                         return -EINTR;
  75         }
  76 }
  77
  78 asmlinkage int
  79 do_rt_sigsuspend(struct pt_regs *regs)
  80 {
  81         sigset_t *unewset = (sigset_t *)regs->er1;
  82         size_t sigsetsize = (size_t)regs->er2;
  83         sigset_t saveset, newset;
  84
  85         /* XXX: Don't preclude handling different sized sigset_t's.  */
  86         if (sigsetsize != sizeof(sigset_t))
  87                 return -EINVAL;
  88
  89         if (copy_from_user(&newset, unewset, sizeof(newset)))
  90                 return -EFAULT;
  91         sigdelsetmask(&newset, ~_BLOCKABLE);
  92
  93         spin_lock_irq(&current->sighand->siglock);
  94         saveset = current->blocked;
  95         current->blocked = newset;
  96         recalc_sigpending();
  97         spin_unlock_irq(&current->sighand->siglock);
  98
  99         regs->er0 = -EINTR;
 100         while (1) {
 101                 current->state = TASK_INTERRUPTIBLE;
 102                 schedule();
 103                 if (do_signal(regs, &saveset))
 104                         return -EINTR;
 105         }
 106 }
 107
 108 asmlinkage int
 109 sys_sigaction(int sig, const struct old_sigaction *act,
 110               struct old_sigaction *oact)
 111 {
 112         struct k_sigaction new_ka, old_ka;
 113         int ret;
 114
 115         if (act) {
 116                 old_sigset_t mask;
 117                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 118                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 119                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 120                         return -EFAULT;
 121                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 122                 __get_user(mask, &act->sa_mask);
 123                 siginitset(&new_ka.sa.sa_mask, mask);
 124         }
 125
 126         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 127
 128         if (!ret && oact) {
 129                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 130                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 131                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 132                         return -EFAULT;
 133                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 134                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 135         }
 136
 137         return ret;
 138 }
 139
 140 asmlinkage int
 141 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
 142 {
 143         return do_sigaltstack(uss, uoss, rdusp());
 144 }
 145
 146
 147 /*
 148  * Do a signal return; undo the signal stack.
 149  *
 150  * Keep the return code on the stack quadword aligned!
 151  * That makes the cache flush below easier.
 152  */
 153
 154 struct sigframe
 155 {
 156         long dummy_er0;
 157         long dummy_vector;
 158 #if defined(CONFIG_CPU_H8S)
 159         short dummy_exr;
 160 #endif
 161         long dummy_pc;
 162         char *pretcode;
 163         unsigned char retcode[8];
 164         unsigned long extramask[_NSIG_WORDS-1];
 165         struct sigcontext sc;
 166         int sig;
 167 } __attribute__((aligned(2),packed));
 168
 169 struct rt_sigframe
 170 {
 171         long dummy_er0;
 172         long dummy_vector;
 173 #if defined(CONFIG_CPU_H8S)
 174         short dummy_exr;
 175 #endif
 176         long dummy_pc;
 177         char *pretcode;
 178         struct siginfo *pinfo;
 179         void *puc;
 180         unsigned char retcode[8];
 181         struct siginfo info;
 182         struct ucontext uc;
 183         int sig;
 184 } __attribute__((aligned(2),packed));
 185
 186 static inline int
 187 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc,
 188                    int *pd0)
 189 {
 190         int err = 0;
 191         unsigned int ccr;
 192         unsigned int usp;
 193         unsigned int er0;
 194
 195         /* Always make any pending restarted system calls return -EINTR */
 196         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 197
 198 #define COPY(r) err |= __get_user(regs->r, &usc->sc_##r)    /* restore passed registers */
 199         COPY(er1);
 200         COPY(er2);
 201         COPY(er3);
 202         COPY(er5);
 203         COPY(pc);
 204         ccr = regs->ccr & 0x10;
 205         COPY(ccr);
 206 #undef COPY
 207         regs->ccr &= 0xef;
 208         regs->ccr |= ccr;
 209         regs->orig_er0 = -1;            /* disable syscall checks */
 210         err |= __get_user(usp, &usc->sc_usp);
 211         wrusp(usp);
 212
 213         err |= __get_user(er0, &usc->sc_er0);
 214         *pd0 = er0;
 215         return err;
 216 }
 217
 218 asmlinkage int do_sigreturn(unsigned long __unused,...)
 219 {
 220         struct pt_regs *regs = (struct pt_regs *) (&__unused - 1);
 221         unsigned long usp = rdusp();
 222         struct sigframe *frame = (struct sigframe *)(usp - 4);
 223         sigset_t set;
 224         int er0;
 225
 226         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 227                 goto badframe;
 228         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
 229             (_NSIG_WORDS > 1 &&
 230              __copy_from_user(&set.sig[1], &frame->extramask,
 231                               sizeof(frame->extramask))))
 232                 goto badframe;
 233
 234         sigdelsetmask(&set, ~_BLOCKABLE);
 235         spin_lock_irq(&current->sighand->siglock);
 236         current->blocked = set;
 237         recalc_sigpending();
 238         spin_unlock_irq(&current->sighand->siglock);
 239
 240         if (restore_sigcontext(regs, &frame->sc, &er0))
 241                 goto badframe;
 242         return er0;
 243
 244 badframe:
 245         force_sig(SIGSEGV, current);
 246         return 0;
 247 }
 248
 249 asmlinkage int do_rt_sigreturn(unsigned long __unused,...)
 250 {
 251         struct pt_regs *regs = (struct pt_regs *) &__unused;
 252         unsigned long usp = rdusp();
 253         struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
 254         sigset_t set;
 255         int er0;
 256
 257         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 258                 goto badframe;
 259         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 260                 goto badframe;
 261
 262         sigdelsetmask(&set, ~_BLOCKABLE);
 263         spin_unlock_irq(&current->sighand->siglock);
 264         current->blocked = set;
 265         recalc_sigpending();
 266         spin_lock_irq(&current->sighand->siglock);
 267
 268         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0))
 269                 goto badframe;
 270
 271         if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
 272                 goto badframe;
 273
 274         return er0;
 275
 276 badframe:
 277         force_sig(SIGSEGV, current);
 278         return 0;
 279 }
 280
 281 static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 282                              unsigned long mask)
 283 {
 284         int err = 0;
 285
 286         err |= __put_user(regs->er0, &sc->sc_er0);
 287         err |= __put_user(regs->er1, &sc->sc_er1);
 288         err |= __put_user(regs->er2, &sc->sc_er2);
 289         err |= __put_user(regs->er3, &sc->sc_er3);
 290         err |= __put_user(regs->er4, &sc->sc_er4);
 291         err |= __put_user(regs->er5, &sc->sc_er5);
 292         err |= __put_user(regs->er6, &sc->sc_er6);
 293         err |= __put_user(rdusp(),   &sc->sc_usp);
 294         err |= __put_user(regs->pc,  &sc->sc_pc);
 295         err |= __put_user(regs->ccr, &sc->sc_ccr);
 296         err |= __put_user(mask,      &sc->sc_mask);
 297
 298         return err;
 299 }
 300
 301 static inline void *
 302 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 303 {
 304         unsigned long usp;
 305
 306         /* Default to using normal stack.  */
 307         usp = rdusp();
 308
 309         /* This is the X/Open sanctioned signal stack switching.  */
 310         if (ka->sa.sa_flags & SA_ONSTACK) {
 311                 if (!sas_ss_flags(usp))
 312                         usp = current->sas_ss_sp + current->sas_ss_size;
 313         }
 314         return (void *)((usp - frame_size) & -8UL);
 315 }
 316
 317 static void setup_frame (int sig, struct k_sigaction *ka,
 318                          sigset_t *set, struct pt_regs *regs)
 319 {
 320         struct sigframe *frame;
 321         int err = 0;
 322         int usig;
 323         unsigned char *ret;
 324
 325         frame = get_sigframe(ka, regs, sizeof(*frame));
 326
 327         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 328                 goto give_sigsegv;
 329
 330         usig = current_thread_info()->exec_domain
 331                 && current_thread_info()->exec_domain->signal_invmap
 332                 && sig < 32
 333                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 334                 : sig;
 335
 336         err |= __put_user(usig, &frame->sig);
 337         if (err)
 338                 goto give_sigsegv;
 339
 340         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 341         if (err)
 342                 goto give_sigsegv;
 343
 344         if (_NSIG_WORDS > 1) {
 345                 err |= copy_to_user(frame->extramask, &set->sig[1],
 346                                     sizeof(frame->extramask));
 347                 if (err)
 348                         goto give_sigsegv;
 349         }
 350
 351         ret = frame->retcode;
 352         if (ka->sa.sa_flags & SA_RESTORER)
 353                 ret = (unsigned char *)(ka->sa.sa_restorer);
 354         else {
 355                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 356                 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 357                                   (unsigned long *)(frame->retcode + 0));
 358                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 359         }
 360
 361         /* Set up to return from userspace.  */
 362         err |= __put_user(ret, &frame->pretcode);
 363
 364         if (err)
 365                 goto give_sigsegv;
 366
 367         /* Set up registers for signal handler */
 368         wrusp ((unsigned long) frame);
 369         regs->pc = (unsigned long) ka->sa.sa_handler;
 370         regs->er0 = (current_thread_info()->exec_domain
 371                            && current_thread_info()->exec_domain->signal_invmap
 372                            && sig < 32
 373                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 374                           : sig);
 375         regs->er1 = (unsigned long)&(frame->sc);
 376         regs->er5 = current->mm->start_data;    /* GOT base */
 377
 378         return;
 379
 380 give_sigsegv:
 381         force_sigsegv(sig, current);
 382 }
 383
 384 static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 385                             sigset_t *set, struct pt_regs *regs)
 386 {
 387         struct rt_sigframe *frame;
 388         int err = 0;
 389         int usig;
 390         unsigned char *ret;
 391
 392         frame = get_sigframe(ka, regs, sizeof(*frame));
 393
 394         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 395                 goto give_sigsegv;
 396
 397         usig = current_thread_info()->exec_domain
 398                 && current_thread_info()->exec_domain->signal_invmap
 399                 && sig < 32
 400                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 401                 : sig;
 402
 403         err |= __put_user(usig, &frame->sig);
 404         if (err)
 405                 goto give_sigsegv;
 406
 407         err |= __put_user(&frame->info, &frame->pinfo);
 408         err |= __put_user(&frame->uc, &frame->puc);
 409         err |= copy_siginfo_to_user(&frame->info, info);
 410         if (err)
 411                 goto give_sigsegv;
 412
 413         /* Create the ucontext.  */
 414         err |= __put_user(0, &frame->uc.uc_flags);
 415         err |= __put_user(0, &frame->uc.uc_link);
 416         err |= __put_user((void *)current->sas_ss_sp,
 417                           &frame->uc.uc_stack.ss_sp);
 418         err |= __put_user(sas_ss_flags(rdusp()),
 419                           &frame->uc.uc_stack.ss_flags);
 420         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 421         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 422         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
 423         if (err)
 424                 goto give_sigsegv;
 425
 426         /* Set up to return from userspace.  */
 427         ret = frame->retcode;
 428         if (ka->sa.sa_flags & SA_RESTORER)
 429                 ret = (unsigned char *)(ka->sa.sa_restorer);
 430         else {
 431                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 432                 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 433                                   (unsigned long *)(frame->retcode + 0));
 434                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 435         }
 436         err |= __put_user(ret, &frame->pretcode);
 437
 438         if (err)
 439                 goto give_sigsegv;
 440
 441         /* Set up registers for signal handler */
 442         wrusp ((unsigned long) frame);
 443         regs->pc  = (unsigned long) ka->sa.sa_handler;
 444         regs->er0 = (current_thread_info()->exec_domain
 445                      && current_thread_info()->exec_domain->signal_invmap
 446                      && sig < 32
 447                      ? current_thread_info()->exec_domain->signal_invmap[sig]
 448                      : sig);
 449         regs->er1 = (unsigned long)&(frame->info);
 450         regs->er2 = (unsigned long)&frame->uc;
 451         regs->er5 = current->mm->start_data;    /* GOT base */
 452
 453         return;
 454
 455 give_sigsegv:
 456         force_sigsegv(sig, current);
 457 }
 458
 459 /*
 460  * OK, we're invoking a handler
 461  */
 462 static void
 463 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 464               sigset_t *oldset, struct pt_regs * regs)
 465 {
 466         /* are we from a system call? */
 467         if (regs->orig_er0 >= 0) {
 468                 switch (regs->er0) {
 469                         case -ERESTART_RESTARTBLOCK:
 470                         case -ERESTARTNOHAND:
 471                                 regs->er0 = -EINTR;
 472                                 break;
 473
 474                         case -ERESTARTSYS:
 475                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 476                                         regs->er0 = -EINTR;
 477                                         break;
 478                                 }
 479                         /* fallthrough */
 480                         case -ERESTARTNOINTR:
 481                                 regs->er0 = regs->orig_er0;
 482                                 regs->pc -= 2;
 483                 }
 484         }
 485
 486         /* set up the stack frame */
 487         if (ka->sa.sa_flags & SA_SIGINFO)
 488                 setup_rt_frame(sig, ka, info, oldset, regs);
 489         else
 490                 setup_frame(sig, ka, oldset, regs);
 491
 492         spin_lock_irq(&current->sighand->siglock);
 493         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 494         if (!(ka->sa.sa_flags & SA_NODEFER))
 495                 sigaddset(&current->blocked,sig);
 496         recalc_sigpending();
 497         spin_unlock_irq(&current->sighand->siglock);
 498 }
 499
 500 /*
 501  * Note that 'init' is a special process: it doesn't get signals it doesn't
 502  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 503  * mistake.
 504  */
 505 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset)
 506 {
 507         siginfo_t info;
 508         int signr;
 509         struct k_sigaction ka;
 510
 511         /*
 512          * We want the common case to go fast, which
 513          * is why we may in certain cases get here from
 514          * kernel mode. Just return without doing anything
 515          * if so.
 516          */
 517         if ((regs->ccr & 0x10))
 518                 return 1;
 519
 520         if (try_to_freeze())
 521                 goto no_signal;
 522
 523         current->thread.esp0 = (unsigned long) regs;
 524
 525         if (!oldset)
 526                 oldset = &current->blocked;
 527
 528         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 529         if (signr > 0) {
 530                 /* Whee!  Actually deliver the signal.  */
 531                 handle_signal(signr, &info, &ka, oldset, regs);
 532                 return 1;
 533         }
 534  no_signal:
 535         /* Did we come from a system call? */
 536         if (regs->orig_er0 >= 0) {
 537                 /* Restart the system call - no handlers present */
 538                 if (regs->er0 == -ERESTARTNOHAND ||
 539                     regs->er0 == -ERESTARTSYS ||
 540                     regs->er0 == -ERESTARTNOINTR) {
 541                         regs->er0 = regs->orig_er0;
 542                         regs->pc -= 2;
 543                 }
 544                 if (regs->er0 == -ERESTART_RESTARTBLOCK){
 545                         regs->er0 = __NR_restart_syscall;
 546                         regs->pc -= 2;
 547                 }
 548         }
 549         return 0;
 550 }
 551
 552 asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
 553 {
 554         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 555                 do_signal(regs, NULL);
 556
 557         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 558                 clear_thread_flag(TIF_NOTIFY_RESUME);
 559                 tracehook_notify_resume(regs);
 560                 if (current->replacement_session_keyring)
 561                         key_replace_session_keyring();
 562         }
 563 }