arch/m32r/kernel/signal.c

   1 /*
   2  *  linux/arch/m32r/kernel/signal.c
   3  *
   4  *  Copyright (c) 2003  Hitoshi Yamamoto
   5  *
   6  *  Taken from i386 version.
   7  *  Copyright (C) 1991, 1992  Linus Torvalds
   8  *
   9  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  10  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/sched.h>
  15 #include <linux/mm.h>
  16 #include <linux/smp.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/kernel.h>
  19 #include <linux/signal.h>
  20 #include <linux/errno.h>
  21 #include <linux/wait.h>
  22 #include <linux/unistd.h>
  23 #include <linux/stddef.h>
  24 #include <linux/personality.h>
  25 #include <linux/suspend.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/ucontext.h>
  28 #include <asm/uaccess.h>
  29
  30 #define DEBUG_SIG 0
  31
  32 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  33
  34 int do_signal(struct pt_regs *, sigset_t *);
  35
  36 /*
  37  * Atomically swap in the new signal mask, and wait for a signal.
  38  */
  39 asmlinkage int
  40 sys_sigsuspend(old_sigset_t mask, unsigned long r1,
  41                unsigned long r2, unsigned long r3, unsigned long r4,
  42                unsigned long r5, unsigned long r6, struct pt_regs regs)
  43 {
  44         sigset_t saveset;
  45
  46         mask &= _BLOCKABLE;
  47         spin_lock_irq(&current->sighand->siglock);
  48         saveset = current->blocked;
  49         siginitset(&current->blocked, mask);
  50         recalc_sigpending();
  51         spin_unlock_irq(&current->sighand->siglock);
  52
  53         regs.r0 = -EINTR;
  54         while (1) {
  55                 current->state = TASK_INTERRUPTIBLE;
  56                 schedule();
  57                 if (do_signal(&regs, &saveset))
  58                         return regs.r0;
  59         }
  60 }
  61
  62 asmlinkage int
  63 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
  64                   unsigned long r2, unsigned long r3, unsigned long r4,
  65                   unsigned long r5, unsigned long r6, struct pt_regs regs)
  66 {
  67         sigset_t saveset, newset;
  68
  69         /* XXX: Don't preclude handling different sized sigset_t's.  */
  70         if (sigsetsize != sizeof(sigset_t))
  71                 return -EINVAL;
  72
  73         if (copy_from_user(&newset, unewset, sizeof(newset)))
  74                 return -EFAULT;
  75         sigdelsetmask(&newset, ~_BLOCKABLE);
  76
  77         spin_lock_irq(&current->sighand->siglock);
  78         saveset = current->blocked;
  79         current->blocked = newset;
  80         recalc_sigpending();
  81         spin_unlock_irq(&current->sighand->siglock);
  82
  83         regs.r0 = -EINTR;
  84         while (1) {
  85                 current->state = TASK_INTERRUPTIBLE;
  86                 schedule();
  87                 if (do_signal(&regs, &saveset))
  88                         return regs.r0;
  89         }
  90 }
  91
  92 asmlinkage int
  93 sys_sigaction(int sig, const struct old_sigaction __user *act,
  94               struct old_sigaction __user *oact)
  95 {
  96         struct k_sigaction new_ka, old_ka;
  97         int ret;
  98
  99         if (act) {
 100                 old_sigset_t mask;
 101                 if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
 102                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
 103                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
 104                         return -EFAULT;
 105                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 106                 __get_user(mask, &act->sa_mask);
 107                 siginitset(&new_ka.sa.sa_mask, mask);
 108         }
 109
 110         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 111
 112         if (!ret && oact) {
 113                 if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
 114                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
 115                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 116                         return -EFAULT;
 117                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 118                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 119         }
 120
 121         return ret;
 122 }
 123
 124 asmlinkage int
 125 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 126                 unsigned long r2, unsigned long r3, unsigned long r4,
 127                 unsigned long r5, unsigned long r6, struct pt_regs regs)
 128 {
 129         return do_sigaltstack(uss, uoss, regs.spu);
 130 }
 131
 132
 133 /*
 134  * Do a signal return; undo the signal stack.
 135  */
 136
 137 struct sigframe
 138 {
 139 //      char *pretcode;
 140         int sig;
 141         struct sigcontext sc;
 142 //      struct _fpstate fpstate;
 143         unsigned long extramask[_NSIG_WORDS-1];
 144         char retcode[4];
 145 };
 146
 147 struct rt_sigframe
 148 {
 149 //      char *pretcode;
 150         int sig;
 151         struct siginfo *pinfo;
 152         void *puc;
 153         struct siginfo info;
 154         struct ucontext uc;
 155 //      struct _fpstate fpstate;
 156         char retcode[8];
 157 };
 158
 159 static int
 160 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 161                    int *r0_p)
 162 {
 163         unsigned int err = 0;
 164
 165         /* Always make any pending restarted system calls return -EINTR */
 166         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 167
 168 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
 169         COPY(r4);
 170         COPY(r5);
 171         COPY(r6);
 172         COPY(pt_regs);
 173         /* COPY(r0); Skip r0 */
 174         COPY(r1);
 175         COPY(r2);
 176         COPY(r3);
 177         COPY(r7);
 178         COPY(r8);
 179         COPY(r9);
 180         COPY(r10);
 181         COPY(r11);
 182         COPY(r12);
 183 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 184         COPY(acc0h);
 185         COPY(acc0l);
 186         COPY(acc1h);
 187         COPY(acc1l);
 188 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 189         COPY(acch);
 190         COPY(accl);
 191 #else
 192 #error unknown isa configuration
 193 #endif
 194         COPY(psw);
 195         COPY(bpc);
 196         COPY(bbpsw);
 197         COPY(bbpc);
 198         COPY(spu);
 199         COPY(fp);
 200         COPY(lr);
 201         COPY(spi);
 202 #undef COPY
 203
 204         regs->syscall_nr = -1;  /* disable syscall checks */
 205         err |= __get_user(*r0_p, &sc->sc_r0);
 206
 207         return err;
 208 }
 209
 210 asmlinkage int
 211 sys_sigreturn(unsigned long r0, unsigned long r1,
 212               unsigned long r2, unsigned long r3, unsigned long r4,
 213               unsigned long r5, unsigned long r6, struct pt_regs regs)
 214 {
 215         struct sigframe __user *frame = (struct sigframe __user *)regs.spu;
 216         sigset_t set;
 217         int result;
 218
 219         if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
 220                 goto badframe;
 221         if (__get_user(set.sig[0], &frame->sc.oldmask)
 222             || (_NSIG_WORDS > 1
 223                 && __copy_from_user(&set.sig[1], &frame->extramask,
 224                                     sizeof(frame->extramask))))
 225                 goto badframe;
 226
 227         sigdelsetmask(&set, ~_BLOCKABLE);
 228         spin_lock_irq(&current->sighand->siglock);
 229         current->blocked = set;
 230         recalc_sigpending();
 231         spin_unlock_irq(&current->sighand->siglock);
 232
 233         if (restore_sigcontext(&regs, &frame->sc, &result))
 234                 goto badframe;
 235         return result;
 236
 237 badframe:
 238         force_sig(SIGSEGV, current);
 239         return 0;
 240 }
 241
 242 asmlinkage int
 243 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 244                  unsigned long r2, unsigned long r3, unsigned long r4,
 245                  unsigned long r5, unsigned long r6, struct pt_regs regs)
 246 {
 247         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs.spu;
 248         sigset_t set;
 249         stack_t st;
 250         int result;
 251
 252         if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
 253                 goto badframe;
 254         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 255                 goto badframe;
 256
 257         sigdelsetmask(&set, ~_BLOCKABLE);
 258         spin_lock_irq(&current->sighand->siglock);
 259         current->blocked = set;
 260         recalc_sigpending();
 261         spin_unlock_irq(&current->sighand->siglock);
 262
 263         if (restore_sigcontext(&regs, &frame->uc.uc_mcontext, &result))
 264                 goto badframe;
 265
 266         if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
 267                 goto badframe;
 268         /* It is more difficult to avoid calling this function than to
 269            call it and ignore errors.  */
 270         do_sigaltstack(&st, NULL, regs.spu);
 271
 272         return result;
 273
 274 badframe:
 275         force_sig(SIGSEGV, current);
 276         return 0;
 277 }
 278
 279 /*
 280  * Set up a signal frame.
 281  */
 282
 283 static int
 284 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 285                  unsigned long mask)
 286 {
 287         int err = 0;
 288
 289 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
 290         COPY(r4);
 291         COPY(r5);
 292         COPY(r6);
 293         COPY(pt_regs);
 294         COPY(r0);
 295         COPY(r1);
 296         COPY(r2);
 297         COPY(r3);
 298         COPY(r7);
 299         COPY(r8);
 300         COPY(r9);
 301         COPY(r10);
 302         COPY(r11);
 303         COPY(r12);
 304 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 305         COPY(acc0h);
 306         COPY(acc0l);
 307         COPY(acc1h);
 308         COPY(acc1l);
 309 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 310         COPY(acch);
 311         COPY(accl);
 312 #else
 313 #error unknown isa configuration
 314 #endif
 315         COPY(psw);
 316         COPY(bpc);
 317         COPY(bbpsw);
 318         COPY(bbpc);
 319         COPY(spu);
 320         COPY(fp);
 321         COPY(lr);
 322         COPY(spi);
 323 #undef COPY
 324
 325         err |= __put_user(mask, &sc->oldmask);
 326
 327         return err;
 328 }
 329
 330 /*
 331  * Determine which stack to use..
 332  */
 333 static inline void __user *
 334 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 335 {
 336         /* This is the X/Open sanctioned signal stack switching.  */
 337         if (ka->sa.sa_flags & SA_ONSTACK) {
 338                 if (sas_ss_flags(sp) == 0)
 339                         sp = current->sas_ss_sp + current->sas_ss_size;
 340         }
 341
 342         return (void __user *)((sp - frame_size) & -8ul);
 343 }
 344
 345 static void setup_frame(int sig, struct k_sigaction *ka,
 346                         sigset_t *set, struct pt_regs *regs)
 347 {
 348         struct sigframe __user *frame;
 349         int err = 0;
 350         int signal;
 351
 352         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 353
 354         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 355                 goto give_sigsegv;
 356
 357         signal = current_thread_info()->exec_domain
 358                 && current_thread_info()->exec_domain->signal_invmap
 359                 && sig < 32
 360                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 361                 : sig;
 362
 363         err |= __put_user(signal, &frame->sig);
 364         if (err)
 365                 goto give_sigsegv;
 366
 367         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 368         if (err)
 369                 goto give_sigsegv;
 370
 371         if (_NSIG_WORDS > 1) {
 372                 err |= __copy_to_user(frame->extramask, &set->sig[1],
 373                                       sizeof(frame->extramask));
 374                 if (err)
 375                         goto give_sigsegv;
 376         }
 377
 378         if (ka->sa.sa_flags & SA_RESTORER)
 379                 regs->lr = (unsigned long)ka->sa.sa_restorer;
 380         else {
 381                 /* This is : ldi r7, #__NR_sigreturn ; trap #2 */
 382                 unsigned long code = 0x670010f2 | (__NR_sigreturn << 16);
 383
 384                 regs->lr = (unsigned long)frame->retcode;
 385                 err |= __put_user(code, (long __user *)(frame->retcode+0));
 386                 if (err)
 387                         goto give_sigsegv;
 388                 flush_cache_sigtramp((unsigned long)frame->retcode);
 389         }
 390
 391         /* Set up registers for signal handler */
 392         regs->spu = (unsigned long)frame;
 393         regs->r0 = signal;      /* Arg for signal handler */
 394         regs->r1 = (unsigned long)&frame->sc;
 395         regs->bpc = (unsigned long)ka->sa.sa_handler;
 396
 397         set_fs(USER_DS);
 398
 399 #if DEBUG_SIG
 400         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 401                 current->comm, current->pid, frame, regs->pc);
 402 #endif
 403
 404         return;
 405
 406 give_sigsegv:
 407         force_sigsegv(sig, current);
 408 }
 409
 410 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 411                            sigset_t *set, struct pt_regs *regs)
 412 {
 413         struct rt_sigframe __user *frame;
 414         int err = 0;
 415         int signal;
 416
 417         frame = get_sigframe(ka, regs->spu, sizeof(*frame));
 418
 419         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 420                 goto give_sigsegv;
 421
 422         signal = current_thread_info()->exec_domain
 423                 && current_thread_info()->exec_domain->signal_invmap
 424                 && sig < 32
 425                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 426                 : sig;
 427
 428         err |= __put_user(signal, &frame->sig);
 429         if (err)
 430                 goto give_sigsegv;
 431
 432         err |= __put_user(&frame->info, &frame->pinfo);
 433         err |= __put_user(&frame->uc, &frame->puc);
 434         err |= copy_siginfo_to_user(&frame->info, info);
 435         if (err)
 436                 goto give_sigsegv;
 437
 438         /* Create the ucontext.  */
 439         err |= __put_user(0, &frame->uc.uc_flags);
 440         err |= __put_user(0, &frame->uc.uc_link);
 441         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 442         err |= __put_user(sas_ss_flags(regs->spu),
 443                           &frame->uc.uc_stack.ss_flags);
 444         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 445         err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 446         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 447         if (err)
 448                 goto give_sigsegv;
 449
 450         /* Set up to return from userspace.  */
 451         if (ka->sa.sa_flags & SA_RESTORER)
 452                 regs->lr = (unsigned long)ka->sa.sa_restorer;
 453         else {
 454                 /* This is : ldi r7, #__NR_rt_sigreturn ; trap #2 */
 455                 unsigned long code1 = 0x97f00000 | (__NR_rt_sigreturn);
 456                 unsigned long code2 = 0x10f2f000;
 457
 458                 regs->lr = (unsigned long)frame->retcode;
 459                 err |= __put_user(code1, (long __user *)(frame->retcode+0));
 460                 err |= __put_user(code2, (long __user *)(frame->retcode+4));
 461                 if (err)
 462                         goto give_sigsegv;
 463                 flush_cache_sigtramp((unsigned long)frame->retcode);
 464         }
 465
 466         /* Set up registers for signal handler */
 467         regs->spu = (unsigned long)frame;
 468         regs->r0 = signal;      /* Arg for signal handler */
 469         regs->r1 = (unsigned long)&frame->info;
 470         regs->r2 = (unsigned long)&frame->uc;
 471         regs->bpc = (unsigned long)ka->sa.sa_handler;
 472
 473         set_fs(USER_DS);
 474
 475 #if DEBUG_SIG
 476         printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 477                 current->comm, current->pid, frame, regs->pc);
 478 #endif
 479
 480         return;
 481
 482 give_sigsegv:
 483         force_sigsegv(sig, current);
 484 }
 485
 486 /*
 487  * OK, we're invoking a handler
 488  */
 489
 490 static void
 491 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 492               sigset_t *oldset, struct pt_regs *regs)
 493 {
 494         unsigned short inst;
 495
 496         /* Are we from a system call? */
 497         if (regs->syscall_nr >= 0) {
 498                 /* If so, check system call restarting.. */
 499                 switch (regs->r0) {
 500                         case -ERESTART_RESTARTBLOCK:
 501                         case -ERESTARTNOHAND:
 502                                 regs->r0 = -EINTR;
 503                                 break;
 504
 505                         case -ERESTARTSYS:
 506                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 507                                         regs->r0 = -EINTR;
 508                                         break;
 509                                 }
 510                         /* fallthrough */
 511                         case -ERESTARTNOINTR:
 512                                 regs->r0 = regs->orig_r0;
 513                                 inst = *(unsigned short *)(regs->bpc - 2);
 514                                 if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 515                                         regs->bpc -= 2;
 516                                 else
 517                                         regs->bpc -= 4;
 518                 }
 519         }
 520
 521         /* Set up the stack frame */
 522         if (ka->sa.sa_flags & SA_SIGINFO)
 523                 setup_rt_frame(sig, ka, info, oldset, regs);
 524         else
 525                 setup_frame(sig, ka, oldset, regs);
 526
 527         if (!(ka->sa.sa_flags & SA_NODEFER)) {
 528                 spin_lock_irq(&current->sighand->siglock);
 529                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 530                 sigaddset(&current->blocked,sig);
 531                 recalc_sigpending();
 532                 spin_unlock_irq(&current->sighand->siglock);
 533         }
 534 }
 535
 536 /*
 537  * Note that 'init' is a special process: it doesn't get signals it doesn't
 538  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 539  * mistake.
 540  */
 541 int do_signal(struct pt_regs *regs, sigset_t *oldset)
 542 {
 543         siginfo_t info;
 544         int signr;
 545         struct k_sigaction ka;
 546         unsigned short inst;
 547
 548         /*
 549          * We want the common case to go fast, which
 550          * is why we may in certain cases get here from
 551          * kernel mode. Just return without doing anything
 552          * if so.
 553          */
 554         if (!user_mode(regs))
 555                 return 1;
 556
 557         if (current->flags & PF_FREEZE) {
 558                 refrigerator(0);
 559                 goto no_signal;
 560         }
 561
 562         if (!oldset)
 563                 oldset = &current->blocked;
 564
 565         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 566         if (signr > 0) {
 567                 /* Reenable any watchpoints before delivering the
 568                  * signal to user space. The processor register will
 569                  * have been cleared if the watchpoint triggered
 570                  * inside the kernel.
 571                  */
 572
 573                 /* Whee!  Actually deliver the signal.  */
 574                 handle_signal(signr, &ka, &info, oldset, regs);
 575                 return 1;
 576         }
 577
 578  no_signal:
 579         /* Did we come from a system call? */
 580         if (regs->syscall_nr >= 0) {
 581                 /* Restart the system call - no handlers present */
 582                 if (regs->r0 == -ERESTARTNOHAND ||
 583                     regs->r0 == -ERESTARTSYS ||
 584                     regs->r0 == -ERESTARTNOINTR) {
 585                         regs->r0 = regs->orig_r0;
 586                         inst = *(unsigned short *)(regs->bpc - 2);
 587                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 588                                 regs->bpc -= 2;
 589                         else
 590                                 regs->bpc -= 4;
 591                 }
 592                 if (regs->r0 == -ERESTART_RESTARTBLOCK){
 593                         regs->r0 = regs->orig_r0;
 594                         regs->r7 = __NR_restart_syscall;
 595                         inst = *(unsigned short *)(regs->bpc - 2);
 596                         if ((inst & 0xfff0) == 0x10f0)  /* trap ? */
 597                                 regs->bpc -= 2;
 598                         else
 599                                 regs->bpc -= 4;
 600                 }
 601         }
 602         return 0;
 603 }
 604
 605 /*
 606  * notification of userspace execution resumption
 607  * - triggered by current->work.notify_resume
 608  */
 609 void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
 610                       __u32 thread_info_flags)
 611 {
 612         /* Pending single-step? */
 613         if (thread_info_flags & _TIF_SINGLESTEP)
 614                 clear_thread_flag(TIF_SINGLESTEP);
 615
 616         /* deal with pending signal delivery */
 617         if (thread_info_flags & _TIF_SIGPENDING)
 618                 do_signal(regs,oldset);
 619
 620         clear_thread_flag(TIF_IRET);
 621 }