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   1 /*
   2  *  linux/arch/sh/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
   7  *
   8  *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
   9  *
  10  */
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/smp.h>
  14 #include <linux/kernel.h>
  15 #include <linux/signal.h>
  16 #include <linux/errno.h>
  17 #include <linux/wait.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/unistd.h>
  20 #include <linux/stddef.h>
  21 #include <linux/tty.h>
  22 #include <linux/elf.h>
  23 #include <linux/personality.h>
  24 #include <linux/binfmts.h>
  25 #include <linux/freezer.h>
  26 #include <asm/system.h>
  27 #include <asm/ucontext.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/cacheflush.h>
  31
  32 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  33
  34 /*
  35  * Atomically swap in the new signal mask, and wait for a signal.
  36  */
  37 asmlinkage int
  38 sys_sigsuspend(old_sigset_t mask,
  39                unsigned long r5, unsigned long r6, unsigned long r7,
  40                struct pt_regs __regs)
  41 {
  42         mask &= _BLOCKABLE;
  43         spin_lock_irq(&current->sighand->siglock);
  44         current->saved_sigmask = current->blocked;
  45         siginitset(&current->blocked, mask);
  46         recalc_sigpending();
  47         spin_unlock_irq(&current->sighand->siglock);
  48
  49         current->state = TASK_INTERRUPTIBLE;
  50         schedule();
  51         set_thread_flag(TIF_RESTORE_SIGMASK);
  52         return -ERESTARTNOHAND;
  53 }
  54
  55 asmlinkage int
  56 sys_sigaction(int sig, const struct old_sigaction __user *act,
  57               struct old_sigaction __user *oact)
  58 {
  59         struct k_sigaction new_ka, old_ka;
  60         int ret;
  61
  62         if (act) {
  63                 old_sigset_t mask;
  64                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
  65                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  66                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
  67                         return -EFAULT;
  68                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
  69                 __get_user(mask, &act->sa_mask);
  70                 siginitset(&new_ka.sa.sa_mask, mask);
  71         }
  72
  73         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  74
  75         if (!ret && oact) {
  76                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
  77                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
  78                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
  79                         return -EFAULT;
  80                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
  81                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
  82         }
  83
  84         return ret;
  85 }
  86
  87 asmlinkage int
  88 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  89                 unsigned long r6, unsigned long r7,
  90                 struct pt_regs __regs)
  91 {
  92         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
  93
  94         return do_sigaltstack(uss, uoss, regs->regs[15]);
  95 }
  96
  97
  98 /*
  99  * Do a signal return; undo the signal stack.
 100  */
 101
 102 #define MOVW(n)  (0x9300|((n)-2))       /* Move mem word at PC+n to R3 */
 103 #if defined(CONFIG_CPU_SH2)
 104 #define TRAP_NOARG 0xc320               /* Syscall w/no args (NR in R3) */
 105 #else
 106 #define TRAP_NOARG 0xc310               /* Syscall w/no args (NR in R3) */
 107 #endif
 108 #define OR_R0_R0 0x200b                 /* or r0,r0 (insert to avoid hardware bug) */
 109
 110 struct sigframe
 111 {
 112         struct sigcontext sc;
 113         unsigned long extramask[_NSIG_WORDS-1];
 114         u16 retcode[8];
 115 };
 116
 117 struct rt_sigframe
 118 {
 119         struct siginfo info;
 120         struct ucontext uc;
 121         u16 retcode[8];
 122 };
 123
 124 #ifdef CONFIG_SH_FPU
 125 static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
 126 {
 127         struct task_struct *tsk = current;
 128
 129         if (!(current_cpu_data.flags & CPU_HAS_FPU))
 130                 return 0;
 131
 132         set_used_math();
 133         return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
 134                                 sizeof(long)*(16*2+2));
 135 }
 136
 137 static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
 138                                       struct pt_regs *regs)
 139 {
 140         struct task_struct *tsk = current;
 141
 142         if (!(current_cpu_data.flags & CPU_HAS_FPU))
 143                 return 0;
 144
 145         if (!used_math()) {
 146                 __put_user(0, &sc->sc_ownedfp);
 147                 return 0;
 148         }
 149
 150         __put_user(1, &sc->sc_ownedfp);
 151
 152         /* This will cause a "finit" to be triggered by the next
 153            attempted FPU operation by the 'current' process.
 154            */
 155         clear_used_math();
 156
 157         unlazy_fpu(tsk, regs);
 158         return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
 159                               sizeof(long)*(16*2+2));
 160 }
 161 #endif /* CONFIG_SH_FPU */
 162
 163 static int
 164 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
 165 {
 166         unsigned int err = 0;
 167
 168 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
 169                         COPY(regs[1]);
 170         COPY(regs[2]);  COPY(regs[3]);
 171         COPY(regs[4]);  COPY(regs[5]);
 172         COPY(regs[6]);  COPY(regs[7]);
 173         COPY(regs[8]);  COPY(regs[9]);
 174         COPY(regs[10]); COPY(regs[11]);
 175         COPY(regs[12]); COPY(regs[13]);
 176         COPY(regs[14]); COPY(regs[15]);
 177         COPY(gbr);      COPY(mach);
 178         COPY(macl);     COPY(pr);
 179         COPY(sr);       COPY(pc);
 180 #undef COPY
 181
 182 #ifdef CONFIG_SH_FPU
 183         if (current_cpu_data.flags & CPU_HAS_FPU) {
 184                 int owned_fp;
 185                 struct task_struct *tsk = current;
 186
 187                 regs->sr |= SR_FD; /* Release FPU */
 188                 clear_fpu(tsk, regs);
 189                 clear_used_math();
 190                 __get_user (owned_fp, &sc->sc_ownedfp);
 191                 if (owned_fp)
 192                         err |= restore_sigcontext_fpu(sc);
 193         }
 194 #endif
 195
 196         regs->tra = -1;         /* disable syscall checks */
 197         err |= __get_user(*r0_p, &sc->sc_regs[0]);
 198         return err;
 199 }
 200
 201 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
 202                              unsigned long r6, unsigned long r7,
 203                              struct pt_regs __regs)
 204 {
 205         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 206         struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
 207         sigset_t set;
 208         int r0;
 209
 210         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 211                 goto badframe;
 212
 213         if (__get_user(set.sig[0], &frame->sc.oldmask)
 214             || (_NSIG_WORDS > 1
 215                 && __copy_from_user(&set.sig[1], &frame->extramask,
 216                                     sizeof(frame->extramask))))
 217                 goto badframe;
 218
 219         sigdelsetmask(&set, ~_BLOCKABLE);
 220
 221         spin_lock_irq(&current->sighand->siglock);
 222         current->blocked = set;
 223         recalc_sigpending();
 224         spin_unlock_irq(&current->sighand->siglock);
 225
 226         if (restore_sigcontext(regs, &frame->sc, &r0))
 227                 goto badframe;
 228         return r0;
 229
 230 badframe:
 231         force_sig(SIGSEGV, current);
 232         return 0;
 233 }
 234
 235 asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
 236                                 unsigned long r6, unsigned long r7,
 237                                 struct pt_regs __regs)
 238 {
 239         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 240         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
 241         sigset_t set;
 242         stack_t st;
 243         int r0;
 244
 245         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 246                 goto badframe;
 247
 248         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 249                 goto badframe;
 250
 251         sigdelsetmask(&set, ~_BLOCKABLE);
 252         spin_lock_irq(&current->sighand->siglock);
 253         current->blocked = set;
 254         recalc_sigpending();
 255         spin_unlock_irq(&current->sighand->siglock);
 256
 257         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
 258                 goto badframe;
 259
 260         if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
 261                 goto badframe;
 262         /* It is more difficult to avoid calling this function than to
 263            call it and ignore errors.  */
 264         do_sigaltstack(&st, NULL, regs->regs[15]);
 265
 266         return r0;
 267
 268 badframe:
 269         force_sig(SIGSEGV, current);
 270         return 0;
 271 }
 272
 273 /*
 274  * Set up a signal frame.
 275  */
 276
 277 static int
 278 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 279                  unsigned long mask)
 280 {
 281         int err = 0;
 282
 283 #define COPY(x)         err |= __put_user(regs->x, &sc->sc_##x)
 284         COPY(regs[0]);  COPY(regs[1]);
 285         COPY(regs[2]);  COPY(regs[3]);
 286         COPY(regs[4]);  COPY(regs[5]);
 287         COPY(regs[6]);  COPY(regs[7]);
 288         COPY(regs[8]);  COPY(regs[9]);
 289         COPY(regs[10]); COPY(regs[11]);
 290         COPY(regs[12]); COPY(regs[13]);
 291         COPY(regs[14]); COPY(regs[15]);
 292         COPY(gbr);      COPY(mach);
 293         COPY(macl);     COPY(pr);
 294         COPY(sr);       COPY(pc);
 295 #undef COPY
 296
 297 #ifdef CONFIG_SH_FPU
 298         err |= save_sigcontext_fpu(sc, regs);
 299 #endif
 300
 301         /* non-iBCS2 extensions.. */
 302         err |= __put_user(mask, &sc->oldmask);
 303
 304         return err;
 305 }
 306
 307 /*
 308  * Determine which stack to use..
 309  */
 310 static inline void __user *
 311 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 312 {
 313         if (ka->sa.sa_flags & SA_ONSTACK) {
 314                 if (sas_ss_flags(sp) == 0)
 315                         sp = current->sas_ss_sp + current->sas_ss_size;
 316         }
 317
 318         return (void __user *)((sp - frame_size) & -8ul);
 319 }
 320
 321 /* These symbols are defined with the addresses in the vsyscall page.
 322    See vsyscall-trapa.S.  */
 323 extern void __user __kernel_sigreturn;
 324 extern void __user __kernel_rt_sigreturn;
 325
 326 static int setup_frame(int sig, struct k_sigaction *ka,
 327                         sigset_t *set, struct pt_regs *regs)
 328 {
 329         struct sigframe __user *frame;
 330         int err = 0;
 331         int signal;
 332
 333         frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
 334
 335         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 336                 goto give_sigsegv;
 337
 338         signal = current_thread_info()->exec_domain
 339                 && current_thread_info()->exec_domain->signal_invmap
 340                 && sig < 32
 341                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 342                 : sig;
 343
 344         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 345
 346         if (_NSIG_WORDS > 1)
 347                 err |= __copy_to_user(frame->extramask, &set->sig[1],
 348                                       sizeof(frame->extramask));
 349
 350         /* Set up to return from userspace.  If provided, use a stub
 351            already in userspace.  */
 352         if (ka->sa.sa_flags & SA_RESTORER) {
 353                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 354 #ifdef CONFIG_VSYSCALL
 355         } else if (likely(current->mm->context.vdso)) {
 356                 regs->pr = VDSO_SYM(&__kernel_sigreturn);
 357 #endif
 358         } else {
 359                 /* Generate return code (system call to sigreturn) */
 360                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 361                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 362                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 363                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 364                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 365                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 366                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 367                 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
 368                 regs->pr = (unsigned long) frame->retcode;
 369         }
 370
 371         if (err)
 372                 goto give_sigsegv;
 373
 374         /* Set up registers for signal handler */
 375         regs->regs[15] = (unsigned long) frame;
 376         regs->regs[4] = signal; /* Arg for signal handler */
 377         regs->regs[5] = 0;
 378         regs->regs[6] = (unsigned long) &frame->sc;
 379         regs->pc = (unsigned long) ka->sa.sa_handler;
 380
 381         set_fs(USER_DS);
 382
 383         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 384                  current->comm, current->pid, frame, regs->pc, regs->pr);
 385
 386         flush_cache_sigtramp(regs->pr);
 387
 388         if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
 389                 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
 390
 391         return 0;
 392
 393 give_sigsegv:
 394         force_sigsegv(sig, current);
 395         return -EFAULT;
 396 }
 397
 398 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 399                            sigset_t *set, struct pt_regs *regs)
 400 {
 401         struct rt_sigframe __user *frame;
 402         int err = 0;
 403         int signal;
 404
 405         frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
 406
 407         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 408                 goto give_sigsegv;
 409
 410         signal = current_thread_info()->exec_domain
 411                 && current_thread_info()->exec_domain->signal_invmap
 412                 && sig < 32
 413                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 414                 : sig;
 415
 416         err |= copy_siginfo_to_user(&frame->info, info);
 417
 418         /* Create the ucontext.  */
 419         err |= __put_user(0, &frame->uc.uc_flags);
 420         err |= __put_user(0, &frame->uc.uc_link);
 421         err |= __put_user((void *)current->sas_ss_sp,
 422                           &frame->uc.uc_stack.ss_sp);
 423         err |= __put_user(sas_ss_flags(regs->regs[15]),
 424                           &frame->uc.uc_stack.ss_flags);
 425         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 426         err |= setup_sigcontext(&frame->uc.uc_mcontext,
 427                                 regs, set->sig[0]);
 428         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 429
 430         /* Set up to return from userspace.  If provided, use a stub
 431            already in userspace.  */
 432         if (ka->sa.sa_flags & SA_RESTORER) {
 433                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 434 #ifdef CONFIG_VSYSCALL
 435         } else if (likely(current->mm->context.vdso)) {
 436                 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
 437 #endif
 438         } else {
 439                 /* Generate return code (system call to rt_sigreturn) */
 440                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 441                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 442                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 443                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 444                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 445                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 446                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 447                 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
 448                 regs->pr = (unsigned long) frame->retcode;
 449         }
 450
 451         if (err)
 452                 goto give_sigsegv;
 453
 454         /* Set up registers for signal handler */
 455         regs->regs[15] = (unsigned long) frame;
 456         regs->regs[4] = signal; /* Arg for signal handler */
 457         regs->regs[5] = (unsigned long) &frame->info;
 458         regs->regs[6] = (unsigned long) &frame->uc;
 459         regs->pc = (unsigned long) ka->sa.sa_handler;
 460
 461         set_fs(USER_DS);
 462
 463         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 464                  current->comm, current->pid, frame, regs->pc, regs->pr);
 465
 466         flush_cache_sigtramp(regs->pr);
 467
 468         if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
 469                 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
 470
 471         return 0;
 472
 473 give_sigsegv:
 474         force_sigsegv(sig, current);
 475         return -EFAULT;
 476 }
 477
 478 /*
 479  * OK, we're invoking a handler
 480  */
 481
 482 static int
 483 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 484               sigset_t *oldset, struct pt_regs *regs)
 485 {
 486         int ret;
 487
 488         /* Are we from a system call? */
 489         if (regs->tra >= 0) {
 490                 /* If so, check system call restarting.. */
 491                 switch (regs->regs[0]) {
 492                         case -ERESTARTNOHAND:
 493                                 regs->regs[0] = -EINTR;
 494                                 break;
 495
 496                         case -ERESTARTSYS:
 497                                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 498                                         regs->regs[0] = -EINTR;
 499                                         break;
 500                                 }
 501                         /* fallthrough */
 502                         case -ERESTARTNOINTR:
 503                                 regs->pc -= instruction_size(
 504                                                 ctrl_inw(regs->pc - 4));
 505                                 break;
 506                 }
 507         } else {
 508                 /* gUSA handling */
 509 #ifdef CONFIG_PREEMPT
 510                 unsigned long flags;
 511
 512                 local_irq_save(flags);
 513 #endif
 514                 if (regs->regs[15] >= 0xc0000000) {
 515                         int offset = (int)regs->regs[15];
 516
 517                         /* Reset stack pointer: clear critical region mark */
 518                         regs->regs[15] = regs->regs[1];
 519                         if (regs->pc < regs->regs[0])
 520                                 /* Go to rewind point #1 */
 521                                 regs->pc = regs->regs[0] + offset -
 522                                         instruction_size(ctrl_inw(regs->pc-4));
 523                 }
 524 #ifdef CONFIG_PREEMPT
 525                 local_irq_restore(flags);
 526 #endif
 527         }
 528
 529         /* Set up the stack frame */
 530         if (ka->sa.sa_flags & SA_SIGINFO)
 531                 ret = setup_rt_frame(sig, ka, info, oldset, regs);
 532         else
 533                 ret = setup_frame(sig, ka, oldset, regs);
 534
 535         if (ka->sa.sa_flags & SA_ONESHOT)
 536                 ka->sa.sa_handler = SIG_DFL;
 537
 538         if (ret == 0) {
 539                 spin_lock_irq(&current->sighand->siglock);
 540                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 541                 if (!(ka->sa.sa_flags & SA_NODEFER))
 542                         sigaddset(&current->blocked,sig);
 543                 recalc_sigpending();
 544                 spin_unlock_irq(&current->sighand->siglock);
 545         }
 546
 547         return ret;
 548 }
 549
 550 /*
 551  * Note that 'init' is a special process: it doesn't get signals it doesn't
 552  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 553  * mistake.
 554  *
 555  * Note that we go through the signals twice: once to check the signals that
 556  * the kernel can handle, and then we build all the user-level signal handling
 557  * stack-frames in one go after that.
 558  */
 559 static void do_signal(struct pt_regs *regs, unsigned int save_r0)
 560 {
 561         siginfo_t info;
 562         int signr;
 563         struct k_sigaction ka;
 564         sigset_t *oldset;
 565
 566         /*
 567          * We want the common case to go fast, which
 568          * is why we may in certain cases get here from
 569          * kernel mode. Just return without doing anything
 570          * if so.
 571          */
 572         if (!user_mode(regs))
 573                 return;
 574
 575         if (try_to_freeze())
 576                 goto no_signal;
 577
 578         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 579                 oldset = &current->saved_sigmask;
 580         else
 581                 oldset = &current->blocked;
 582
 583         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 584         if (signr > 0) {
 585                 /* Whee!  Actually deliver the signal.  */
 586                 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
 587                         /* a signal was successfully delivered; the saved
 588                          * sigmask will have been stored in the signal frame,
 589                          * and will be restored by sigreturn, so we can simply
 590                          * clear the TIF_RESTORE_SIGMASK flag */
 591                         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 592                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 593                 }
 594
 595                 return;
 596         }
 597
 598  no_signal:
 599         /* Did we come from a system call? */
 600         if (regs->tra >= 0) {
 601                 /* Restart the system call - no handlers present */
 602                 if (regs->regs[0] == -ERESTARTNOHAND ||
 603                     regs->regs[0] == -ERESTARTSYS ||
 604                     regs->regs[0] == -ERESTARTNOINTR) {
 605                         regs->regs[0] = save_r0;
 606                         regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 607                 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
 608                         regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 609                         regs->regs[3] = __NR_restart_syscall;
 610                 }
 611         }
 612
 613         /* if there's no signal to deliver, we just put the saved sigmask
 614          * back */
 615         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 616                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 617                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 618         }
 619 }
 620
 621 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
 622                                  __u32 thread_info_flags)
 623 {
 624         /* deal with pending signal delivery */
 625         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 626                 do_signal(regs, save_r0);
 627 }