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 /*
  51  * Atomically swap in the new signal mask, and wait for a signal.
  52  */
  53 asmlinkage int
  54 sys_sigsuspend(int unused1, int unused2, old_sigset_t mask)
  55 {
  56         sigset_t blocked;
  57         siginitset(&blocked, mask);
  58         return sigsuspend(&blocked);
  59 }
  60
  61 asmlinkage int
  62 sys_sigaction(int sig, const struct old_sigaction *act,
  63               struct old_sigaction *oact)
  64 {
  65         struct k_sigaction new_ka, old_ka;
  66         int ret;
  67
  68         if (act) {
  69                 old_sigset_t mask;
  70                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
  71                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  72                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
  73                     __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
  74                     __get_user(mask, &act->sa_mask))
  75                         return -EFAULT;
  76                 siginitset(&new_ka.sa.sa_mask, mask);
  77         }
  78
  79         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  80
  81         if (!ret && oact) {
  82                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
  83                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
  84                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
  85                     __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
  86                     __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
  87                         return -EFAULT;
  88         }
  89
  90         return ret;
  91 }
  92
  93 asmlinkage int
  94 sys_sigaltstack(const stack_t *uss, stack_t *uoss)
  95 {
  96         return do_sigaltstack(uss, uoss, rdusp());
  97 }
  98
  99
 100 /*
 101  * Do a signal return; undo the signal stack.
 102  *
 103  * Keep the return code on the stack quadword aligned!
 104  * That makes the cache flush below easier.
 105  */
 106
 107 struct sigframe
 108 {
 109         long dummy_er0;
 110         long dummy_vector;
 111 #if defined(CONFIG_CPU_H8S)
 112         short dummy_exr;
 113 #endif
 114         long dummy_pc;
 115         char *pretcode;
 116         unsigned char retcode[8];
 117         unsigned long extramask[_NSIG_WORDS-1];
 118         struct sigcontext sc;
 119         int sig;
 120 } __attribute__((aligned(2),packed));
 121
 122 struct rt_sigframe
 123 {
 124         long dummy_er0;
 125         long dummy_vector;
 126 #if defined(CONFIG_CPU_H8S)
 127         short dummy_exr;
 128 #endif
 129         long dummy_pc;
 130         char *pretcode;
 131         struct siginfo *pinfo;
 132         void *puc;
 133         unsigned char retcode[8];
 134         struct siginfo info;
 135         struct ucontext uc;
 136         int sig;
 137 } __attribute__((aligned(2),packed));
 138
 139 static inline int
 140 restore_sigcontext(struct pt_regs *regs, struct sigcontext *usc,
 141                    int *pd0)
 142 {
 143         int err = 0;
 144         unsigned int ccr;
 145         unsigned int usp;
 146         unsigned int er0;
 147
 148         /* Always make any pending restarted system calls return -EINTR */
 149         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 150
 151 #define COPY(r) err |= __get_user(regs->r, &usc->sc_##r)    /* restore passed registers */
 152         COPY(er1);
 153         COPY(er2);
 154         COPY(er3);
 155         COPY(er5);
 156         COPY(pc);
 157         ccr = regs->ccr & 0x10;
 158         COPY(ccr);
 159 #undef COPY
 160         regs->ccr &= 0xef;
 161         regs->ccr |= ccr;
 162         regs->orig_er0 = -1;            /* disable syscall checks */
 163         err |= __get_user(usp, &usc->sc_usp);
 164         wrusp(usp);
 165
 166         err |= __get_user(er0, &usc->sc_er0);
 167         *pd0 = er0;
 168         return err;
 169 }
 170
 171 asmlinkage int do_sigreturn(unsigned long __unused,...)
 172 {
 173         struct pt_regs *regs = (struct pt_regs *) (&__unused - 1);
 174         unsigned long usp = rdusp();
 175         struct sigframe *frame = (struct sigframe *)(usp - 4);
 176         sigset_t set;
 177         int er0;
 178
 179         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 180                 goto badframe;
 181         if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
 182             (_NSIG_WORDS > 1 &&
 183              __copy_from_user(&set.sig[1], &frame->extramask,
 184                               sizeof(frame->extramask))))
 185                 goto badframe;
 186
 187         set_current_blocked(&set);
 188
 189         if (restore_sigcontext(regs, &frame->sc, &er0))
 190                 goto badframe;
 191         return er0;
 192
 193 badframe:
 194         force_sig(SIGSEGV, current);
 195         return 0;
 196 }
 197
 198 asmlinkage int do_rt_sigreturn(unsigned long __unused,...)
 199 {
 200         struct pt_regs *regs = (struct pt_regs *) &__unused;
 201         unsigned long usp = rdusp();
 202         struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
 203         sigset_t set;
 204         int er0;
 205
 206         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 207                 goto badframe;
 208         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 209                 goto badframe;
 210
 211         set_current_blocked(&set);
 212
 213         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &er0))
 214                 goto badframe;
 215
 216         if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
 217                 goto badframe;
 218
 219         return er0;
 220
 221 badframe:
 222         force_sig(SIGSEGV, current);
 223         return 0;
 224 }
 225
 226 static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 227                              unsigned long mask)
 228 {
 229         int err = 0;
 230
 231         err |= __put_user(regs->er0, &sc->sc_er0);
 232         err |= __put_user(regs->er1, &sc->sc_er1);
 233         err |= __put_user(regs->er2, &sc->sc_er2);
 234         err |= __put_user(regs->er3, &sc->sc_er3);
 235         err |= __put_user(regs->er4, &sc->sc_er4);
 236         err |= __put_user(regs->er5, &sc->sc_er5);
 237         err |= __put_user(regs->er6, &sc->sc_er6);
 238         err |= __put_user(rdusp(),   &sc->sc_usp);
 239         err |= __put_user(regs->pc,  &sc->sc_pc);
 240         err |= __put_user(regs->ccr, &sc->sc_ccr);
 241         err |= __put_user(mask,      &sc->sc_mask);
 242
 243         return err;
 244 }
 245
 246 static inline void *
 247 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 248 {
 249         unsigned long usp;
 250
 251         /* Default to using normal stack.  */
 252         usp = rdusp();
 253
 254         /* This is the X/Open sanctioned signal stack switching.  */
 255         if (ka->sa.sa_flags & SA_ONSTACK) {
 256                 if (!sas_ss_flags(usp))
 257                         usp = current->sas_ss_sp + current->sas_ss_size;
 258         }
 259         return (void *)((usp - frame_size) & -8UL);
 260 }
 261
 262 static int setup_frame (int sig, struct k_sigaction *ka,
 263                          sigset_t *set, struct pt_regs *regs)
 264 {
 265         struct sigframe *frame;
 266         int err = 0;
 267         int usig;
 268         unsigned char *ret;
 269
 270         frame = get_sigframe(ka, regs, sizeof(*frame));
 271
 272         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 273                 goto give_sigsegv;
 274
 275         usig = current_thread_info()->exec_domain
 276                 && current_thread_info()->exec_domain->signal_invmap
 277                 && sig < 32
 278                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 279                 : sig;
 280
 281         err |= __put_user(usig, &frame->sig);
 282         if (err)
 283                 goto give_sigsegv;
 284
 285         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 286         if (err)
 287                 goto give_sigsegv;
 288
 289         if (_NSIG_WORDS > 1) {
 290                 err |= copy_to_user(frame->extramask, &set->sig[1],
 291                                     sizeof(frame->extramask));
 292                 if (err)
 293                         goto give_sigsegv;
 294         }
 295
 296         ret = frame->retcode;
 297         if (ka->sa.sa_flags & SA_RESTORER)
 298                 ret = (unsigned char *)(ka->sa.sa_restorer);
 299         else {
 300                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 301                 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 302                                   (unsigned long *)(frame->retcode + 0));
 303                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 304         }
 305
 306         /* Set up to return from userspace.  */
 307         err |= __put_user(ret, &frame->pretcode);
 308
 309         if (err)
 310                 goto give_sigsegv;
 311
 312         /* Set up registers for signal handler */
 313         wrusp ((unsigned long) frame);
 314         regs->pc = (unsigned long) ka->sa.sa_handler;
 315         regs->er0 = (current_thread_info()->exec_domain
 316                            && current_thread_info()->exec_domain->signal_invmap
 317                            && sig < 32
 318                            ? current_thread_info()->exec_domain->signal_invmap[sig]
 319                           : sig);
 320         regs->er1 = (unsigned long)&(frame->sc);
 321         regs->er5 = current->mm->start_data;    /* GOT base */
 322
 323         return 0;
 324
 325 give_sigsegv:
 326         force_sigsegv(sig, current);
 327         return -EFAULT;
 328 }
 329
 330 static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 331                             sigset_t *set, struct pt_regs *regs)
 332 {
 333         struct rt_sigframe *frame;
 334         int err = 0;
 335         int usig;
 336         unsigned char *ret;
 337
 338         frame = get_sigframe(ka, regs, sizeof(*frame));
 339
 340         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 341                 goto give_sigsegv;
 342
 343         usig = current_thread_info()->exec_domain
 344                 && current_thread_info()->exec_domain->signal_invmap
 345                 && sig < 32
 346                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 347                 : sig;
 348
 349         err |= __put_user(usig, &frame->sig);
 350         if (err)
 351                 goto give_sigsegv;
 352
 353         err |= __put_user(&frame->info, &frame->pinfo);
 354         err |= __put_user(&frame->uc, &frame->puc);
 355         err |= copy_siginfo_to_user(&frame->info, info);
 356         if (err)
 357                 goto give_sigsegv;
 358
 359         /* Create the ucontext.  */
 360         err |= __put_user(0, &frame->uc.uc_flags);
 361         err |= __put_user(0, &frame->uc.uc_link);
 362         err |= __put_user((void *)current->sas_ss_sp,
 363                           &frame->uc.uc_stack.ss_sp);
 364         err |= __put_user(sas_ss_flags(rdusp()),
 365                           &frame->uc.uc_stack.ss_flags);
 366         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 367         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 368         err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
 369         if (err)
 370                 goto give_sigsegv;
 371
 372         /* Set up to return from userspace.  */
 373         ret = frame->retcode;
 374         if (ka->sa.sa_flags & SA_RESTORER)
 375                 ret = (unsigned char *)(ka->sa.sa_restorer);
 376         else {
 377                 /* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
 378                 err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
 379                                   (unsigned long *)(frame->retcode + 0));
 380                 err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
 381         }
 382         err |= __put_user(ret, &frame->pretcode);
 383
 384         if (err)
 385                 goto give_sigsegv;
 386
 387         /* Set up registers for signal handler */
 388         wrusp ((unsigned long) frame);
 389         regs->pc  = (unsigned long) ka->sa.sa_handler;
 390         regs->er0 = (current_thread_info()->exec_domain
 391                      && current_thread_info()->exec_domain->signal_invmap
 392                      && sig < 32
 393                      ? current_thread_info()->exec_domain->signal_invmap[sig]
 394                      : sig);
 395         regs->er1 = (unsigned long)&(frame->info);
 396         regs->er2 = (unsigned long)&frame->uc;
 397         regs->er5 = current->mm->start_data;    /* GOT base */
 398
 399         return 0;
 400
 401 give_sigsegv:
 402         force_sigsegv(sig, current);
 403         return -EFAULT;
 404 }
 405
 406 /*
 407  * OK, we're invoking a handler
 408  */
 409 static void
 410 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 411               struct pt_regs * regs)
 412 {
 413         sigset_t *oldset = sigmask_to_save();
 414         int ret;
 415         /* are we from a system call? */
 416         if (regs->orig_er0 >= 0) {
 417                 switch (regs->er0) {
 418                         case -ERESTART_RESTARTBLOCK:
 419                         case -ERESTARTNOHAND:
 420                                 regs->er0 = -EINTR;
 421                                 break;
 422
 423                         case -ERESTARTSYS:
 424                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 425                                         regs->er0 = -EINTR;
 426                                         break;
 427                                 }
 428                         /* fallthrough */
 429                         case -ERESTARTNOINTR:
 430                                 regs->er0 = regs->orig_er0;
 431                                 regs->pc -= 2;
 432                 }
 433         }
 434
 435         /* set up the stack frame */
 436         if (ka->sa.sa_flags & SA_SIGINFO)
 437                 ret = setup_rt_frame(sig, ka, info, oldset, regs);
 438         else
 439                 ret = setup_frame(sig, ka, oldset, regs);
 440
 441         if (!ret)
 442                 signal_delivered(sig, info, ka, regs, 0);
 443 }
 444
 445 /*
 446  * Note that 'init' is a special process: it doesn't get signals it doesn't
 447  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 448  * mistake.
 449  */
 450 static void do_signal(struct pt_regs *regs)
 451 {
 452         siginfo_t info;
 453         int signr;
 454         struct k_sigaction ka;
 455
 456         /*
 457          * We want the common case to go fast, which
 458          * is why we may in certain cases get here from
 459          * kernel mode. Just return without doing anything
 460          * if so.
 461          */
 462         if ((regs->ccr & 0x10))
 463                 return;
 464
 465         current->thread.esp0 = (unsigned long) regs;
 466
 467         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 468         if (signr > 0) {
 469                 /* Whee!  Actually deliver the signal.  */
 470                 handle_signal(signr, &info, &ka, regs);
 471                 return;
 472         }
 473         /* Did we come from a system call? */
 474         if (regs->orig_er0 >= 0) {
 475                 /* Restart the system call - no handlers present */
 476                 if (regs->er0 == -ERESTARTNOHAND ||
 477                     regs->er0 == -ERESTARTSYS ||
 478                     regs->er0 == -ERESTARTNOINTR) {
 479                         regs->er0 = regs->orig_er0;
 480                         regs->pc -= 2;
 481                 }
 482                 if (regs->er0 == -ERESTART_RESTARTBLOCK){
 483                         regs->er0 = __NR_restart_syscall;
 484                         regs->pc -= 2;
 485                 }
 486         }
 487
 488         /* If there's no signal to deliver, we just restore the saved mask.  */
 489         restore_saved_sigmask();
 490 }
 491
 492 asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
 493 {
 494         if (thread_info_flags & _TIF_SIGPENDING)
 495                 do_signal(regs);
 496
 497         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 498                 clear_thread_flag(TIF_NOTIFY_RESUME);
 499                 tracehook_notify_resume(regs);
 500         }
 501 }