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