arch/sh/kernel/signal_32.c

   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 <linux/io.h>
  27 #include <linux/tracehook.h>
  28 #include <asm/system.h>
  29 #include <asm/ucontext.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/cacheflush.h>
  33 #include <asm/fpu.h>
  34
  35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  36
  37 struct fdpic_func_descriptor {
  38         unsigned long   text;
  39         unsigned long   GOT;
  40 };
  41
  42 /*
  43  * Atomically swap in the new signal mask, and wait for a signal.
  44  */
  45 asmlinkage int
  46 sys_sigsuspend(old_sigset_t mask,
  47                unsigned long r5, unsigned long r6, unsigned long r7,
  48                struct pt_regs __regs)
  49 {
  50         mask &= _BLOCKABLE;
  51         spin_lock_irq(&current->sighand->siglock);
  52         current->saved_sigmask = current->blocked;
  53         siginitset(&current->blocked, mask);
  54         recalc_sigpending();
  55         spin_unlock_irq(&current->sighand->siglock);
  56
  57         current->state = TASK_INTERRUPTIBLE;
  58         schedule();
  59         set_thread_flag(TIF_RESTORE_SIGMASK);
  60         return -ERESTARTNOHAND;
  61 }
  62
  63 asmlinkage int
  64 sys_sigaction(int sig, const struct old_sigaction __user *act,
  65               struct old_sigaction __user *oact)
  66 {
  67         struct k_sigaction new_ka, old_ka;
  68         int ret;
  69
  70         if (act) {
  71                 old_sigset_t mask;
  72                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
  73                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  74                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
  75                         return -EFAULT;
  76                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
  77                 __get_user(mask, &act->sa_mask);
  78                 siginitset(&new_ka.sa.sa_mask, mask);
  79         }
  80
  81         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  82
  83         if (!ret && oact) {
  84                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
  85                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
  86                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
  87                         return -EFAULT;
  88                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
  89                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
  90         }
  91
  92         return ret;
  93 }
  94
  95 asmlinkage int
  96 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
  97                 unsigned long r6, unsigned long r7,
  98                 struct pt_regs __regs)
  99 {
 100         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 101
 102         return do_sigaltstack(uss, uoss, regs->regs[15]);
 103 }
 104
 105
 106 /*
 107  * Do a signal return; undo the signal stack.
 108  */
 109
 110 #define MOVW(n)  (0x9300|((n)-2))       /* Move mem word at PC+n to R3 */
 111 #if defined(CONFIG_CPU_SH2)
 112 #define TRAP_NOARG 0xc320               /* Syscall w/no args (NR in R3) */
 113 #else
 114 #define TRAP_NOARG 0xc310               /* Syscall w/no args (NR in R3) */
 115 #endif
 116 #define OR_R0_R0 0x200b                 /* or r0,r0 (insert to avoid hardware bug) */
 117
 118 struct sigframe
 119 {
 120         struct sigcontext sc;
 121         unsigned long extramask[_NSIG_WORDS-1];
 122         u16 retcode[8];
 123 };
 124
 125 struct rt_sigframe
 126 {
 127         struct siginfo info;
 128         struct ucontext uc;
 129         u16 retcode[8];
 130 };
 131
 132 #ifdef CONFIG_SH_FPU
 133 static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
 134 {
 135         struct task_struct *tsk = current;
 136
 137         if (!(current_cpu_data.flags & CPU_HAS_FPU))
 138                 return 0;
 139
 140         set_used_math();
 141         return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
 142                                 sizeof(long)*(16*2+2));
 143 }
 144
 145 static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
 146                                       struct pt_regs *regs)
 147 {
 148         struct task_struct *tsk = current;
 149
 150         if (!(current_cpu_data.flags & CPU_HAS_FPU))
 151                 return 0;
 152
 153         if (!used_math()) {
 154                 __put_user(0, &sc->sc_ownedfp);
 155                 return 0;
 156         }
 157
 158         __put_user(1, &sc->sc_ownedfp);
 159
 160         /* This will cause a "finit" to be triggered by the next
 161            attempted FPU operation by the 'current' process.
 162            */
 163         clear_used_math();
 164
 165         unlazy_fpu(tsk, regs);
 166         return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
 167                               sizeof(long)*(16*2+2));
 168 }
 169 #endif /* CONFIG_SH_FPU */
 170
 171 static int
 172 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
 173 {
 174         unsigned int err = 0;
 175
 176 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
 177                         COPY(regs[1]);
 178         COPY(regs[2]);  COPY(regs[3]);
 179         COPY(regs[4]);  COPY(regs[5]);
 180         COPY(regs[6]);  COPY(regs[7]);
 181         COPY(regs[8]);  COPY(regs[9]);
 182         COPY(regs[10]); COPY(regs[11]);
 183         COPY(regs[12]); COPY(regs[13]);
 184         COPY(regs[14]); COPY(regs[15]);
 185         COPY(gbr);      COPY(mach);
 186         COPY(macl);     COPY(pr);
 187         COPY(sr);       COPY(pc);
 188 #undef COPY
 189
 190 #ifdef CONFIG_SH_FPU
 191         if (current_cpu_data.flags & CPU_HAS_FPU) {
 192                 int owned_fp;
 193                 struct task_struct *tsk = current;
 194
 195                 regs->sr |= SR_FD; /* Release FPU */
 196                 clear_fpu(tsk, regs);
 197                 clear_used_math();
 198                 __get_user (owned_fp, &sc->sc_ownedfp);
 199                 if (owned_fp)
 200                         err |= restore_sigcontext_fpu(sc);
 201         }
 202 #endif
 203
 204         regs->tra = -1;         /* disable syscall checks */
 205         err |= __get_user(*r0_p, &sc->sc_regs[0]);
 206         return err;
 207 }
 208
 209 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
 210                              unsigned long r6, unsigned long r7,
 211                              struct pt_regs __regs)
 212 {
 213         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 214         struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
 215         sigset_t set;
 216         int r0;
 217
 218         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 219                 goto badframe;
 220
 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
 229         spin_lock_irq(&current->sighand->siglock);
 230         current->blocked = set;
 231         recalc_sigpending();
 232         spin_unlock_irq(&current->sighand->siglock);
 233
 234         if (restore_sigcontext(regs, &frame->sc, &r0))
 235                 goto badframe;
 236         return r0;
 237
 238 badframe:
 239         force_sig(SIGSEGV, current);
 240         return 0;
 241 }
 242
 243 asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
 244                                 unsigned long r6, unsigned long r7,
 245                                 struct pt_regs __regs)
 246 {
 247         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 248         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
 249         sigset_t set;
 250         stack_t st;
 251         int r0;
 252
 253         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 254                 goto badframe;
 255
 256         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 257                 goto badframe;
 258
 259         sigdelsetmask(&set, ~_BLOCKABLE);
 260         spin_lock_irq(&current->sighand->siglock);
 261         current->blocked = set;
 262         recalc_sigpending();
 263         spin_unlock_irq(&current->sighand->siglock);
 264
 265         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
 266                 goto badframe;
 267
 268         if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
 269                 goto badframe;
 270         /* It is more difficult to avoid calling this function than to
 271            call it and ignore errors.  */
 272         do_sigaltstack((const stack_t __user *)&st, NULL, (unsigned long)frame);
 273
 274         return r0;
 275
 276 badframe:
 277         force_sig(SIGSEGV, current);
 278         return 0;
 279 }
 280
 281 /*
 282  * Set up a signal frame.
 283  */
 284
 285 static int
 286 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 287                  unsigned long mask)
 288 {
 289         int err = 0;
 290
 291 #define COPY(x)         err |= __put_user(regs->x, &sc->sc_##x)
 292         COPY(regs[0]);  COPY(regs[1]);
 293         COPY(regs[2]);  COPY(regs[3]);
 294         COPY(regs[4]);  COPY(regs[5]);
 295         COPY(regs[6]);  COPY(regs[7]);
 296         COPY(regs[8]);  COPY(regs[9]);
 297         COPY(regs[10]); COPY(regs[11]);
 298         COPY(regs[12]); COPY(regs[13]);
 299         COPY(regs[14]); COPY(regs[15]);
 300         COPY(gbr);      COPY(mach);
 301         COPY(macl);     COPY(pr);
 302         COPY(sr);       COPY(pc);
 303 #undef COPY
 304
 305 #ifdef CONFIG_SH_FPU
 306         err |= save_sigcontext_fpu(sc, regs);
 307 #endif
 308
 309         /* non-iBCS2 extensions.. */
 310         err |= __put_user(mask, &sc->oldmask);
 311
 312         return err;
 313 }
 314
 315 /*
 316  * Determine which stack to use..
 317  */
 318 static inline void __user *
 319 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 320 {
 321         if (ka->sa.sa_flags & SA_ONSTACK) {
 322                 if (sas_ss_flags(sp) == 0)
 323                         sp = current->sas_ss_sp + current->sas_ss_size;
 324         }
 325
 326         return (void __user *)((sp - frame_size) & -8ul);
 327 }
 328
 329 /* These symbols are defined with the addresses in the vsyscall page.
 330    See vsyscall-trapa.S.  */
 331 extern void __user __kernel_sigreturn;
 332 extern void __user __kernel_rt_sigreturn;
 333
 334 static int setup_frame(int sig, struct k_sigaction *ka,
 335                         sigset_t *set, struct pt_regs *regs)
 336 {
 337         struct sigframe __user *frame;
 338         int err = 0;
 339         int signal;
 340
 341         frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
 342
 343         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 344                 goto give_sigsegv;
 345
 346         signal = current_thread_info()->exec_domain
 347                 && current_thread_info()->exec_domain->signal_invmap
 348                 && sig < 32
 349                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 350                 : sig;
 351
 352         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 353
 354         if (_NSIG_WORDS > 1)
 355                 err |= __copy_to_user(frame->extramask, &set->sig[1],
 356                                       sizeof(frame->extramask));
 357
 358         /* Set up to return from userspace.  If provided, use a stub
 359            already in userspace.  */
 360         if (ka->sa.sa_flags & SA_RESTORER) {
 361                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 362 #ifdef CONFIG_VSYSCALL
 363         } else if (likely(current->mm->context.vdso)) {
 364                 regs->pr = VDSO_SYM(&__kernel_sigreturn);
 365 #endif
 366         } else {
 367                 /* Generate return code (system call to sigreturn) */
 368                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 369                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 370                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 371                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 372                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 373                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 374                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 375                 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
 376                 regs->pr = (unsigned long) frame->retcode;
 377                 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
 378         }
 379
 380         if (err)
 381                 goto give_sigsegv;
 382
 383         /* Set up registers for signal handler */
 384         regs->regs[15] = (unsigned long) frame;
 385         regs->regs[4] = signal; /* Arg for signal handler */
 386         regs->regs[5] = 0;
 387         regs->regs[6] = (unsigned long) &frame->sc;
 388
 389         if (current->personality & FDPIC_FUNCPTRS) {
 390                 struct fdpic_func_descriptor __user *funcptr =
 391                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 392
 393                 __get_user(regs->pc, &funcptr->text);
 394                 __get_user(regs->regs[12], &funcptr->GOT);
 395         } else
 396                 regs->pc = (unsigned long)ka->sa.sa_handler;
 397
 398         set_fs(USER_DS);
 399
 400         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 401                  current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
 402
 403         return 0;
 404
 405 give_sigsegv:
 406         force_sigsegv(sig, current);
 407         return -EFAULT;
 408 }
 409
 410 static int 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->regs[15], 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 |= copy_siginfo_to_user(&frame->info, info);
 429
 430         /* Create the ucontext.  */
 431         err |= __put_user(0, &frame->uc.uc_flags);
 432         err |= __put_user(0, &frame->uc.uc_link);
 433         err |= __put_user((void *)current->sas_ss_sp,
 434                           &frame->uc.uc_stack.ss_sp);
 435         err |= __put_user(sas_ss_flags(regs->regs[15]),
 436                           &frame->uc.uc_stack.ss_flags);
 437         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 438         err |= setup_sigcontext(&frame->uc.uc_mcontext,
 439                                 regs, set->sig[0]);
 440         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 441
 442         /* Set up to return from userspace.  If provided, use a stub
 443            already in userspace.  */
 444         if (ka->sa.sa_flags & SA_RESTORER) {
 445                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 446 #ifdef CONFIG_VSYSCALL
 447         } else if (likely(current->mm->context.vdso)) {
 448                 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
 449 #endif
 450         } else {
 451                 /* Generate return code (system call to rt_sigreturn) */
 452                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 453                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 454                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 455                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 456                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 457                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 458                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 459                 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
 460                 regs->pr = (unsigned long) frame->retcode;
 461         }
 462
 463         if (err)
 464                 goto give_sigsegv;
 465
 466         /* Set up registers for signal handler */
 467         regs->regs[15] = (unsigned long) frame;
 468         regs->regs[4] = signal; /* Arg for signal handler */
 469         regs->regs[5] = (unsigned long) &frame->info;
 470         regs->regs[6] = (unsigned long) &frame->uc;
 471
 472         if (current->personality & FDPIC_FUNCPTRS) {
 473                 struct fdpic_func_descriptor __user *funcptr =
 474                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 475
 476                 __get_user(regs->pc, &funcptr->text);
 477                 __get_user(regs->regs[12], &funcptr->GOT);
 478         } else
 479                 regs->pc = (unsigned long)ka->sa.sa_handler;
 480
 481         set_fs(USER_DS);
 482
 483         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 484                  current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
 485
 486         flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
 487
 488         return 0;
 489
 490 give_sigsegv:
 491         force_sigsegv(sig, current);
 492         return -EFAULT;
 493 }
 494
 495 /*
 496  * OK, we're invoking a handler
 497  */
 498
 499 static int
 500 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 501               sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0)
 502 {
 503         int ret;
 504
 505         /* Are we from a system call? */
 506         if (regs->tra >= 0) {
 507                 /* If so, check system call restarting.. */
 508                 switch (regs->regs[0]) {
 509                         case -ERESTART_RESTARTBLOCK:
 510                         case -ERESTARTNOHAND:
 511                         no_system_call_restart:
 512                                 regs->regs[0] = -EINTR;
 513                                 break;
 514
 515                         case -ERESTARTSYS:
 516                                 if (!(ka->sa.sa_flags & SA_RESTART))
 517                                         goto no_system_call_restart;
 518                         /* fallthrough */
 519                         case -ERESTARTNOINTR:
 520                                 regs->regs[0] = save_r0;
 521                                 regs->pc -= instruction_size(
 522                                                 ctrl_inw(regs->pc - 4));
 523                                 break;
 524                 }
 525         }
 526
 527         /* Set up the stack frame */
 528         if (ka->sa.sa_flags & SA_SIGINFO)
 529                 ret = setup_rt_frame(sig, ka, info, oldset, regs);
 530         else
 531                 ret = setup_frame(sig, ka, oldset, regs);
 532
 533         if (ka->sa.sa_flags & SA_ONESHOT)
 534                 ka->sa.sa_handler = SIG_DFL;
 535
 536         if (ret == 0) {
 537                 spin_lock_irq(&current->sighand->siglock);
 538                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 539                 if (!(ka->sa.sa_flags & SA_NODEFER))
 540                         sigaddset(&current->blocked,sig);
 541                 recalc_sigpending();
 542                 spin_unlock_irq(&current->sighand->siglock);
 543         }
 544
 545         return ret;
 546 }
 547
 548 /*
 549  * Note that 'init' is a special process: it doesn't get signals it doesn't
 550  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 551  * mistake.
 552  *
 553  * Note that we go through the signals twice: once to check the signals that
 554  * the kernel can handle, and then we build all the user-level signal handling
 555  * stack-frames in one go after that.
 556  */
 557 static void do_signal(struct pt_regs *regs, unsigned int save_r0)
 558 {
 559         siginfo_t info;
 560         int signr;
 561         struct k_sigaction ka;
 562         sigset_t *oldset;
 563
 564         /*
 565          * We want the common case to go fast, which
 566          * is why we may in certain cases get here from
 567          * kernel mode. Just return without doing anything
 568          * if so.
 569          */
 570         if (!user_mode(regs))
 571                 return;
 572
 573         if (try_to_freeze())
 574                 goto no_signal;
 575
 576         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 577                 oldset = &current->saved_sigmask;
 578         else
 579                 oldset = &current->blocked;
 580
 581         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 582         if (signr > 0) {
 583                 /* Whee!  Actually deliver the signal.  */
 584                 if (handle_signal(signr, &ka, &info, oldset,
 585                                   regs, save_r0) == 0) {
 586                         /* a signal was successfully delivered; the saved
 587                          * sigmask will have been stored in the signal frame,
 588                          * and will be restored by sigreturn, so we can simply
 589                          * clear the TIF_RESTORE_SIGMASK flag */
 590                         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 591                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 592
 593                         tracehook_signal_handler(signr, &info, &ka, regs,
 594                                         test_thread_flag(TIF_SINGLESTEP));
 595                 }
 596
 597                 return;
 598         }
 599
 600 no_signal:
 601         /* Did we come from a system call? */
 602         if (regs->tra >= 0) {
 603                 /* Restart the system call - no handlers present */
 604                 if (regs->regs[0] == -ERESTARTNOHAND ||
 605                     regs->regs[0] == -ERESTARTSYS ||
 606                     regs->regs[0] == -ERESTARTNOINTR) {
 607                         regs->regs[0] = save_r0;
 608                         regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 609                 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
 610                         regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 611                         regs->regs[3] = __NR_restart_syscall;
 612                 }
 613         }
 614
 615         /* if there's no signal to deliver, we just put the saved sigmask
 616          * back */
 617         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 618                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 619                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 620         }
 621 }
 622
 623 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
 624                                  unsigned long thread_info_flags)
 625 {
 626         /* deal with pending signal delivery */
 627         if (thread_info_flags & _TIF_SIGPENDING)
 628                 do_signal(regs, save_r0);
 629
 630         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 631                 clear_thread_flag(TIF_NOTIFY_RESUME);
 632                 tracehook_notify_resume(regs);
 633         }
 634 }