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/syscalls.h>
  34 #include <asm/fpu.h>
  35
  36 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  37
  38 struct fdpic_func_descriptor {
  39         unsigned long   text;
  40         unsigned long   GOT;
  41 };
  42
  43 /*
  44  * The following define adds a 64 byte gap between the signal
  45  * stack frame and previous contents of the stack.  This allows
  46  * frame unwinding in a function epilogue but only if a frame
  47  * pointer is used in the function.  This is necessary because
  48  * current gcc compilers (<4.3) do not generate unwind info on
  49  * SH for function epilogues.
  50  */
  51 #define UNWINDGUARD 64
  52
  53 /*
  54  * Atomically swap in the new signal mask, and wait for a signal.
  55  */
  56 asmlinkage int
  57 sys_sigsuspend(old_sigset_t mask,
  58                unsigned long r5, unsigned long r6, unsigned long r7,
  59                struct pt_regs __regs)
  60 {
  61         sigset_t blocked;
  62
  63         current->saved_sigmask = current->blocked;
  64
  65         mask &= _BLOCKABLE;
  66         siginitset(&blocked, mask);
  67         set_current_blocked(&blocked);
  68
  69         current->state = TASK_INTERRUPTIBLE;
  70         schedule();
  71         set_restore_sigmask();
  72
  73         return -ERESTARTNOHAND;
  74 }
  75
  76 asmlinkage int
  77 sys_sigaction(int sig, const struct old_sigaction __user *act,
  78               struct old_sigaction __user *oact)
  79 {
  80         struct k_sigaction new_ka, old_ka;
  81         int ret;
  82
  83         if (act) {
  84                 old_sigset_t mask;
  85                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
  86                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
  87                     __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
  88                         return -EFAULT;
  89                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
  90                 __get_user(mask, &act->sa_mask);
  91                 siginitset(&new_ka.sa.sa_mask, mask);
  92         }
  93
  94         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
  95
  96         if (!ret && oact) {
  97                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
  98                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
  99                     __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
 100                         return -EFAULT;
 101                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 102                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 103         }
 104
 105         return ret;
 106 }
 107
 108 asmlinkage int
 109 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 110                 unsigned long r6, unsigned long r7,
 111                 struct pt_regs __regs)
 112 {
 113         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 114
 115         return do_sigaltstack(uss, uoss, regs->regs[15]);
 116 }
 117
 118
 119 /*
 120  * Do a signal return; undo the signal stack.
 121  */
 122
 123 #define MOVW(n)  (0x9300|((n)-2))       /* Move mem word at PC+n to R3 */
 124 #if defined(CONFIG_CPU_SH2)
 125 #define TRAP_NOARG 0xc320               /* Syscall w/no args (NR in R3) */
 126 #else
 127 #define TRAP_NOARG 0xc310               /* Syscall w/no args (NR in R3) */
 128 #endif
 129 #define OR_R0_R0 0x200b                 /* or r0,r0 (insert to avoid hardware bug) */
 130
 131 struct sigframe
 132 {
 133         struct sigcontext sc;
 134         unsigned long extramask[_NSIG_WORDS-1];
 135         u16 retcode[8];
 136 };
 137
 138 struct rt_sigframe
 139 {
 140         struct siginfo info;
 141         struct ucontext uc;
 142         u16 retcode[8];
 143 };
 144
 145 #ifdef CONFIG_SH_FPU
 146 static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
 147 {
 148         struct task_struct *tsk = current;
 149
 150         if (!(boot_cpu_data.flags & CPU_HAS_FPU))
 151                 return 0;
 152
 153         set_used_math();
 154         return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
 155                                 sizeof(long)*(16*2+2));
 156 }
 157
 158 static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
 159                                       struct pt_regs *regs)
 160 {
 161         struct task_struct *tsk = current;
 162
 163         if (!(boot_cpu_data.flags & CPU_HAS_FPU))
 164                 return 0;
 165
 166         if (!used_math()) {
 167                 __put_user(0, &sc->sc_ownedfp);
 168                 return 0;
 169         }
 170
 171         __put_user(1, &sc->sc_ownedfp);
 172
 173         /* This will cause a "finit" to be triggered by the next
 174            attempted FPU operation by the 'current' process.
 175            */
 176         clear_used_math();
 177
 178         unlazy_fpu(tsk, regs);
 179         return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
 180                               sizeof(long)*(16*2+2));
 181 }
 182 #endif /* CONFIG_SH_FPU */
 183
 184 static int
 185 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
 186 {
 187         unsigned int err = 0;
 188
 189 #define COPY(x)         err |= __get_user(regs->x, &sc->sc_##x)
 190                         COPY(regs[1]);
 191         COPY(regs[2]);  COPY(regs[3]);
 192         COPY(regs[4]);  COPY(regs[5]);
 193         COPY(regs[6]);  COPY(regs[7]);
 194         COPY(regs[8]);  COPY(regs[9]);
 195         COPY(regs[10]); COPY(regs[11]);
 196         COPY(regs[12]); COPY(regs[13]);
 197         COPY(regs[14]); COPY(regs[15]);
 198         COPY(gbr);      COPY(mach);
 199         COPY(macl);     COPY(pr);
 200         COPY(sr);       COPY(pc);
 201 #undef COPY
 202
 203 #ifdef CONFIG_SH_FPU
 204         if (boot_cpu_data.flags & CPU_HAS_FPU) {
 205                 int owned_fp;
 206                 struct task_struct *tsk = current;
 207
 208                 regs->sr |= SR_FD; /* Release FPU */
 209                 clear_fpu(tsk, regs);
 210                 clear_used_math();
 211                 __get_user (owned_fp, &sc->sc_ownedfp);
 212                 if (owned_fp)
 213                         err |= restore_sigcontext_fpu(sc);
 214         }
 215 #endif
 216
 217         regs->tra = -1;         /* disable syscall checks */
 218         err |= __get_user(*r0_p, &sc->sc_regs[0]);
 219         return err;
 220 }
 221
 222 asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
 223                              unsigned long r6, unsigned long r7,
 224                              struct pt_regs __regs)
 225 {
 226         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 227         struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
 228         sigset_t set;
 229         int r0;
 230
 231         /* Always make any pending restarted system calls return -EINTR */
 232         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 233
 234         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 235                 goto badframe;
 236
 237         if (__get_user(set.sig[0], &frame->sc.oldmask)
 238             || (_NSIG_WORDS > 1
 239                 && __copy_from_user(&set.sig[1], &frame->extramask,
 240                                     sizeof(frame->extramask))))
 241                 goto badframe;
 242
 243         sigdelsetmask(&set, ~_BLOCKABLE);
 244         set_current_blocked(&set);
 245
 246         if (restore_sigcontext(regs, &frame->sc, &r0))
 247                 goto badframe;
 248         return r0;
 249
 250 badframe:
 251         force_sig(SIGSEGV, current);
 252         return 0;
 253 }
 254
 255 asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
 256                                 unsigned long r6, unsigned long r7,
 257                                 struct pt_regs __regs)
 258 {
 259         struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
 260         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
 261         sigset_t set;
 262         int r0;
 263
 264         /* Always make any pending restarted system calls return -EINTR */
 265         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 266
 267         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 268                 goto badframe;
 269
 270         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 271                 goto badframe;
 272
 273         sigdelsetmask(&set, ~_BLOCKABLE);
 274         set_current_blocked(&set);
 275
 276         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
 277                 goto badframe;
 278
 279         if (do_sigaltstack(&frame->uc.uc_stack, NULL,
 280                            regs->regs[15]) == -EFAULT)
 281                 goto badframe;
 282
 283         return r0;
 284
 285 badframe:
 286         force_sig(SIGSEGV, current);
 287         return 0;
 288 }
 289
 290 /*
 291  * Set up a signal frame.
 292  */
 293
 294 static int
 295 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 296                  unsigned long mask)
 297 {
 298         int err = 0;
 299
 300 #define COPY(x)         err |= __put_user(regs->x, &sc->sc_##x)
 301         COPY(regs[0]);  COPY(regs[1]);
 302         COPY(regs[2]);  COPY(regs[3]);
 303         COPY(regs[4]);  COPY(regs[5]);
 304         COPY(regs[6]);  COPY(regs[7]);
 305         COPY(regs[8]);  COPY(regs[9]);
 306         COPY(regs[10]); COPY(regs[11]);
 307         COPY(regs[12]); COPY(regs[13]);
 308         COPY(regs[14]); COPY(regs[15]);
 309         COPY(gbr);      COPY(mach);
 310         COPY(macl);     COPY(pr);
 311         COPY(sr);       COPY(pc);
 312 #undef COPY
 313
 314 #ifdef CONFIG_SH_FPU
 315         err |= save_sigcontext_fpu(sc, regs);
 316 #endif
 317
 318         /* non-iBCS2 extensions.. */
 319         err |= __put_user(mask, &sc->oldmask);
 320
 321         return err;
 322 }
 323
 324 /*
 325  * Determine which stack to use..
 326  */
 327 static inline void __user *
 328 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 329 {
 330         if (ka->sa.sa_flags & SA_ONSTACK) {
 331                 if (sas_ss_flags(sp) == 0)
 332                         sp = current->sas_ss_sp + current->sas_ss_size;
 333         }
 334
 335         return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
 336 }
 337
 338 /* These symbols are defined with the addresses in the vsyscall page.
 339    See vsyscall-trapa.S.  */
 340 extern void __kernel_sigreturn(void);
 341 extern void __kernel_rt_sigreturn(void);
 342
 343 static int setup_frame(int sig, struct k_sigaction *ka,
 344                         sigset_t *set, struct pt_regs *regs)
 345 {
 346         struct sigframe __user *frame;
 347         int err = 0;
 348         int signal;
 349
 350         frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
 351
 352         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 353                 goto give_sigsegv;
 354
 355         signal = current_thread_info()->exec_domain
 356                 && current_thread_info()->exec_domain->signal_invmap
 357                 && sig < 32
 358                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 359                 : sig;
 360
 361         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 362
 363         if (_NSIG_WORDS > 1)
 364                 err |= __copy_to_user(frame->extramask, &set->sig[1],
 365                                       sizeof(frame->extramask));
 366
 367         /* Set up to return from userspace.  If provided, use a stub
 368            already in userspace.  */
 369         if (ka->sa.sa_flags & SA_RESTORER) {
 370                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 371 #ifdef CONFIG_VSYSCALL
 372         } else if (likely(current->mm->context.vdso)) {
 373                 regs->pr = VDSO_SYM(&__kernel_sigreturn);
 374 #endif
 375         } else {
 376                 /* Generate return code (system call to sigreturn) */
 377                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 378                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 379                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 380                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 381                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 382                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 383                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 384                 err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
 385                 regs->pr = (unsigned long) frame->retcode;
 386                 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
 387         }
 388
 389         if (err)
 390                 goto give_sigsegv;
 391
 392         /* Set up registers for signal handler */
 393         regs->regs[15] = (unsigned long) frame;
 394         regs->regs[4] = signal; /* Arg for signal handler */
 395         regs->regs[5] = 0;
 396         regs->regs[6] = (unsigned long) &frame->sc;
 397
 398         if (current->personality & FDPIC_FUNCPTRS) {
 399                 struct fdpic_func_descriptor __user *funcptr =
 400                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 401
 402                 __get_user(regs->pc, &funcptr->text);
 403                 __get_user(regs->regs[12], &funcptr->GOT);
 404         } else
 405                 regs->pc = (unsigned long)ka->sa.sa_handler;
 406
 407         set_fs(USER_DS);
 408
 409         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 410                  current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
 411
 412         return 0;
 413
 414 give_sigsegv:
 415         force_sigsegv(sig, current);
 416         return -EFAULT;
 417 }
 418
 419 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 420                            sigset_t *set, struct pt_regs *regs)
 421 {
 422         struct rt_sigframe __user *frame;
 423         int err = 0;
 424         int signal;
 425
 426         frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
 427
 428         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 429                 goto give_sigsegv;
 430
 431         signal = current_thread_info()->exec_domain
 432                 && current_thread_info()->exec_domain->signal_invmap
 433                 && sig < 32
 434                 ? current_thread_info()->exec_domain->signal_invmap[sig]
 435                 : sig;
 436
 437         err |= copy_siginfo_to_user(&frame->info, info);
 438
 439         /* Create the ucontext.  */
 440         err |= __put_user(0, &frame->uc.uc_flags);
 441         err |= __put_user(NULL, &frame->uc.uc_link);
 442         err |= __put_user((void *)current->sas_ss_sp,
 443                           &frame->uc.uc_stack.ss_sp);
 444         err |= __put_user(sas_ss_flags(regs->regs[15]),
 445                           &frame->uc.uc_stack.ss_flags);
 446         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 447         err |= setup_sigcontext(&frame->uc.uc_mcontext,
 448                                 regs, set->sig[0]);
 449         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 450
 451         /* Set up to return from userspace.  If provided, use a stub
 452            already in userspace.  */
 453         if (ka->sa.sa_flags & SA_RESTORER) {
 454                 regs->pr = (unsigned long) ka->sa.sa_restorer;
 455 #ifdef CONFIG_VSYSCALL
 456         } else if (likely(current->mm->context.vdso)) {
 457                 regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
 458 #endif
 459         } else {
 460                 /* Generate return code (system call to rt_sigreturn) */
 461                 err |= __put_user(MOVW(7), &frame->retcode[0]);
 462                 err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
 463                 err |= __put_user(OR_R0_R0, &frame->retcode[2]);
 464                 err |= __put_user(OR_R0_R0, &frame->retcode[3]);
 465                 err |= __put_user(OR_R0_R0, &frame->retcode[4]);
 466                 err |= __put_user(OR_R0_R0, &frame->retcode[5]);
 467                 err |= __put_user(OR_R0_R0, &frame->retcode[6]);
 468                 err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
 469                 regs->pr = (unsigned long) frame->retcode;
 470                 flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
 471         }
 472
 473         if (err)
 474                 goto give_sigsegv;
 475
 476         /* Set up registers for signal handler */
 477         regs->regs[15] = (unsigned long) frame;
 478         regs->regs[4] = signal; /* Arg for signal handler */
 479         regs->regs[5] = (unsigned long) &frame->info;
 480         regs->regs[6] = (unsigned long) &frame->uc;
 481
 482         if (current->personality & FDPIC_FUNCPTRS) {
 483                 struct fdpic_func_descriptor __user *funcptr =
 484                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 485
 486                 __get_user(regs->pc, &funcptr->text);
 487                 __get_user(regs->regs[12], &funcptr->GOT);
 488         } else
 489                 regs->pc = (unsigned long)ka->sa.sa_handler;
 490
 491         set_fs(USER_DS);
 492
 493         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
 494                  current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
 495
 496         return 0;
 497
 498 give_sigsegv:
 499         force_sigsegv(sig, current);
 500         return -EFAULT;
 501 }
 502
 503 static inline void
 504 handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
 505                        struct sigaction *sa)
 506 {
 507         /* If we're not from a syscall, bail out */
 508         if (regs->tra < 0)
 509                 return;
 510
 511         /* check for system call restart.. */
 512         switch (regs->regs[0]) {
 513                 case -ERESTART_RESTARTBLOCK:
 514                 case -ERESTARTNOHAND:
 515                 no_system_call_restart:
 516                         regs->regs[0] = -EINTR;
 517                         break;
 518
 519                 case -ERESTARTSYS:
 520                         if (!(sa->sa_flags & SA_RESTART))
 521                                 goto no_system_call_restart;
 522                 /* fallthrough */
 523                 case -ERESTARTNOINTR:
 524                         regs->regs[0] = save_r0;
 525                         regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
 526                         break;
 527         }
 528 }
 529
 530 /*
 531  * OK, we're invoking a handler
 532  */
 533 static int
 534 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 535               sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0)
 536 {
 537         int ret;
 538
 539         /* Set up the stack frame */
 540         if (ka->sa.sa_flags & SA_SIGINFO)
 541                 ret = setup_rt_frame(sig, ka, info, oldset, regs);
 542         else
 543                 ret = setup_frame(sig, ka, oldset, regs);
 544
 545         if (ret == 0)
 546                 block_sigmask(ka, sig);
 547
 548         return ret;
 549 }
 550
 551 /*
 552  * Note that 'init' is a special process: it doesn't get signals it doesn't
 553  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 554  * mistake.
 555  *
 556  * Note that we go through the signals twice: once to check the signals that
 557  * the kernel can handle, and then we build all the user-level signal handling
 558  * stack-frames in one go after that.
 559  */
 560 static void do_signal(struct pt_regs *regs, unsigned int save_r0)
 561 {
 562         siginfo_t info;
 563         int signr;
 564         struct k_sigaction ka;
 565         sigset_t *oldset;
 566
 567         /*
 568          * We want the common case to go fast, which
 569          * is why we may in certain cases get here from
 570          * kernel mode. Just return without doing anything
 571          * if so.
 572          */
 573         if (!user_mode(regs))
 574                 return;
 575
 576         if (try_to_freeze())
 577                 goto no_signal;
 578
 579         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 580                 oldset = &current->saved_sigmask;
 581         else
 582                 oldset = &current->blocked;
 583
 584         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 585         if (signr > 0) {
 586                 handle_syscall_restart(save_r0, regs, &ka.sa);
 587
 588                 /* Whee!  Actually deliver the signal.  */
 589                 if (handle_signal(signr, &ka, &info, oldset,
 590                                   regs, save_r0) == 0) {
 591                         /*
 592                          * A signal was successfully delivered; the saved
 593                          * sigmask will have been stored in the signal frame,
 594                          * and will be restored by sigreturn, so we can simply
 595                          * clear the TS_RESTORE_SIGMASK flag
 596                          */
 597                         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 598
 599                         tracehook_signal_handler(signr, &info, &ka, regs,
 600                                         test_thread_flag(TIF_SINGLESTEP));
 601                 }
 602
 603                 return;
 604         }
 605
 606 no_signal:
 607         /* Did we come from a system call? */
 608         if (regs->tra >= 0) {
 609                 /* Restart the system call - no handlers present */
 610                 if (regs->regs[0] == -ERESTARTNOHAND ||
 611                     regs->regs[0] == -ERESTARTSYS ||
 612                     regs->regs[0] == -ERESTARTNOINTR) {
 613                         regs->regs[0] = save_r0;
 614                         regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
 615                 } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
 616                         regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
 617                         regs->regs[3] = __NR_restart_syscall;
 618                 }
 619         }
 620
 621         /*
 622          * If there's no signal to deliver, we just put the saved sigmask
 623          * back.
 624          */
 625         if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
 626                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 627                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 628         }
 629 }
 630
 631 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
 632                                  unsigned long thread_info_flags)
 633 {
 634         /* deal with pending signal delivery */
 635         if (thread_info_flags & _TIF_SIGPENDING)
 636                 do_signal(regs, save_r0);
 637
 638         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 639                 clear_thread_flag(TIF_NOTIFY_RESUME);
 640                 tracehook_notify_resume(regs);
 641                 if (current->replacement_session_keyring)
 642                         key_replace_session_keyring();
 643         }
 644 }