kernel/arch/sparc/kernel/signal_64.c

   1 /*
   2  *  arch/sparc64/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
   6  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
   7  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
   8  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   9  */
  10
  11 #ifdef CONFIG_COMPAT
  12 #include <linux/compat.h>       /* for compat_old_sigset_t */
  13 #endif
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/signal.h>
  17 #include <linux/errno.h>
  18 #include <linux/wait.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/tracehook.h>
  21 #include <linux/unistd.h>
  22 #include <linux/mm.h>
  23 #include <linux/tty.h>
  24 #include <linux/binfmts.h>
  25 #include <linux/bitops.h>
  26 #include <linux/context_tracking.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/ptrace.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/fpumacro.h>
  32 #include <asm/uctx.h>
  33 #include <asm/siginfo.h>
  34 #include <asm/visasm.h>
  35 #include <asm/switch_to.h>
  36 #include <asm/cacheflush.h>
  37
  38 #include "sigutil.h"
  39 #include "systbls.h"
  40 #include "kernel.h"
  41 #include "entry.h"
  42
  43 /* {set, get}context() needed for 64-bit SparcLinux userland. */
  44 asmlinkage void sparc64_set_context(struct pt_regs *regs)
  45 {
  46         struct ucontext __user *ucp = (struct ucontext __user *)
  47                 regs->u_regs[UREG_I0];
  48         enum ctx_state prev_state = exception_enter();
  49         mc_gregset_t __user *grp;
  50         unsigned long pc, npc, tstate;
  51         unsigned long fp, i7;
  52         unsigned char fenab;
  53         int err;
  54
  55         flush_user_windows();
  56         if (get_thread_wsaved()                                 ||
  57             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
  58             (!__access_ok(ucp, sizeof(*ucp))))
  59                 goto do_sigsegv;
  60         grp  = &ucp->uc_mcontext.mc_gregs;
  61         err  = __get_user(pc, &((*grp)[MC_PC]));
  62         err |= __get_user(npc, &((*grp)[MC_NPC]));
  63         if (err || ((pc | npc) & 3))
  64                 goto do_sigsegv;
  65         if (regs->u_regs[UREG_I1]) {
  66                 sigset_t set;
  67
  68                 if (_NSIG_WORDS == 1) {
  69                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
  70                                 goto do_sigsegv;
  71                 } else {
  72                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
  73                                 goto do_sigsegv;
  74                 }
  75                 set_current_blocked(&set);
  76         }
  77         if (test_thread_flag(TIF_32BIT)) {
  78                 pc &= 0xffffffff;
  79                 npc &= 0xffffffff;
  80         }
  81         regs->tpc = pc;
  82         regs->tnpc = npc;
  83         err |= __get_user(regs->y, &((*grp)[MC_Y]));
  84         err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
  85         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
  86         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
  87         err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
  88         err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
  89         err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
  90         err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
  91         err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
  92         err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
  93
  94         /* Skip %g7 as that's the thread register in userspace.  */
  95
  96         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
  97         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
  98         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
  99         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
 100         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
 101         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
 102         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
 103         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
 104
 105         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 106         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 107         err |= __put_user(fp,
 108               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 109         err |= __put_user(i7,
 110               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 111
 112         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 113         if (fenab) {
 114                 unsigned long *fpregs = current_thread_info()->fpregs;
 115                 unsigned long fprs;
 116
 117                 fprs_write(0);
 118                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 119                 if (fprs & FPRS_DL)
 120                         err |= copy_from_user(fpregs,
 121                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 122                                               (sizeof(unsigned int) * 32));
 123                 if (fprs & FPRS_DU)
 124                         err |= copy_from_user(fpregs+16,
 125                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 126                          (sizeof(unsigned int) * 32));
 127                 err |= __get_user(current_thread_info()->xfsr[0],
 128                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 129                 err |= __get_user(current_thread_info()->gsr[0],
 130                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 131                 regs->tstate &= ~TSTATE_PEF;
 132         }
 133         if (err)
 134                 goto do_sigsegv;
 135 out:
 136         exception_exit(prev_state);
 137         return;
 138 do_sigsegv:
 139         force_sig(SIGSEGV, current);
 140         goto out;
 141 }
 142
 143 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 144 {
 145         struct ucontext __user *ucp = (struct ucontext __user *)
 146                 regs->u_regs[UREG_I0];
 147         enum ctx_state prev_state = exception_enter();
 148         mc_gregset_t __user *grp;
 149         mcontext_t __user *mcp;
 150         unsigned long fp, i7;
 151         unsigned char fenab;
 152         int err;
 153
 154         synchronize_user_stack();
 155         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 156                 goto do_sigsegv;
 157
 158 #if 1
 159         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 160 #else
 161         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 162 #endif
 163
 164         mcp = &ucp->uc_mcontext;
 165         grp = &mcp->mc_gregs;
 166
 167         /* Skip over the trap instruction, first. */
 168         if (test_thread_flag(TIF_32BIT)) {
 169                 regs->tpc   = (regs->tnpc & 0xffffffff);
 170                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 171         } else {
 172                 regs->tpc   = regs->tnpc;
 173                 regs->tnpc += 4;
 174         }
 175         err = 0;
 176         if (_NSIG_WORDS == 1)
 177                 err |= __put_user(current->blocked.sig[0],
 178                                   (unsigned long __user *)&ucp->uc_sigmask);
 179         else
 180                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 181                                       sizeof(sigset_t));
 182
 183         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 184         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 185         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 186         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 187         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 188         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 189         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 190         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 191         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 192         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 193         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 194         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 195         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 196         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 197         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 198         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 199         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 200         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 201         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 202
 203         err |= __get_user(fp,
 204                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 205         err |= __get_user(i7,
 206                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 207         err |= __put_user(fp, &(mcp->mc_fp));
 208         err |= __put_user(i7, &(mcp->mc_i7));
 209
 210         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 211         if (fenab) {
 212                 unsigned long *fpregs = current_thread_info()->fpregs;
 213                 unsigned long fprs;
 214
 215                 fprs = current_thread_info()->fpsaved[0];
 216                 if (fprs & FPRS_DL)
 217                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 218                                             (sizeof(unsigned int) * 32));
 219                 if (fprs & FPRS_DU)
 220                         err |= copy_to_user(
 221                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 222                           (sizeof(unsigned int) * 32));
 223                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 224                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 225                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 226         }
 227         if (err)
 228                 goto do_sigsegv;
 229 out:
 230         exception_exit(prev_state);
 231         return;
 232 do_sigsegv:
 233         force_sig(SIGSEGV, current);
 234         goto out;
 235 }
 236
 237 struct rt_signal_frame {
 238         struct sparc_stackf     ss;
 239         siginfo_t               info;
 240         struct pt_regs          regs;
 241         __siginfo_fpu_t __user  *fpu_save;
 242         stack_t                 stack;
 243         sigset_t                mask;
 244         __siginfo_rwin_t        *rwin_save;
 245 };
 246
 247 void do_rt_sigreturn(struct pt_regs *regs)
 248 {
 249         struct rt_signal_frame __user *sf;
 250         unsigned long tpc, tnpc, tstate;
 251         __siginfo_fpu_t __user *fpu_save;
 252         __siginfo_rwin_t __user *rwin_save;
 253         sigset_t set;
 254         int err;
 255
 256         /* Always make any pending restarted system calls return -EINTR */
 257         current->restart_block.fn = do_no_restart_syscall;
 258
 259         synchronize_user_stack ();
 260         sf = (struct rt_signal_frame __user *)
 261                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 262
 263         /* 1. Make sure we are not getting garbage from the user */
 264         if (((unsigned long) sf) & 3)
 265                 goto segv;
 266
 267         err = get_user(tpc, &sf->regs.tpc);
 268         err |= __get_user(tnpc, &sf->regs.tnpc);
 269         if (test_thread_flag(TIF_32BIT)) {
 270                 tpc &= 0xffffffff;
 271                 tnpc &= 0xffffffff;
 272         }
 273         err |= ((tpc | tnpc) & 3);
 274
 275         /* 2. Restore the state */
 276         err |= __get_user(regs->y, &sf->regs.y);
 277         err |= __get_user(tstate, &sf->regs.tstate);
 278         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 279
 280         /* User can only change condition codes and %asi in %tstate. */
 281         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 282         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 283
 284         err |= __get_user(fpu_save, &sf->fpu_save);
 285         if (!err && fpu_save)
 286                 err |= restore_fpu_state(regs, fpu_save);
 287
 288         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 289         err |= restore_altstack(&sf->stack);
 290         if (err)
 291                 goto segv;
 292
 293         err |= __get_user(rwin_save, &sf->rwin_save);
 294         if (!err && rwin_save) {
 295                 if (restore_rwin_state(rwin_save))
 296                         goto segv;
 297         }
 298
 299         regs->tpc = tpc;
 300         regs->tnpc = tnpc;
 301
 302         /* Prevent syscall restart.  */
 303         pt_regs_clear_syscall(regs);
 304
 305         set_current_blocked(&set);
 306         return;
 307 segv:
 308         force_sig(SIGSEGV, current);
 309 }
 310
 311 /* Checks if the fp is valid */
 312 static int invalid_frame_pointer(void __user *fp)
 313 {
 314         if (((unsigned long) fp) & 15)
 315                 return 1;
 316         return 0;
 317 }
 318
 319 static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
 320 {
 321         unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 322
 323         /*
 324          * If we are on the alternate signal stack and would overflow it, don't.
 325          * Return an always-bogus address instead so we will die with SIGSEGV.
 326          */
 327         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 328                 return (void __user *) -1L;
 329
 330         /* This is the X/Open sanctioned signal stack switching.  */
 331         sp = sigsp(sp, ksig) - framesize;
 332
 333         /* Always align the stack frame.  This handles two cases.  First,
 334          * sigaltstack need not be mindful of platform specific stack
 335          * alignment.  Second, if we took this signal because the stack
 336          * is not aligned properly, we'd like to take the signal cleanly
 337          * and report that.
 338          */
 339         sp &= ~15UL;
 340
 341         return (void __user *) sp;
 342 }
 343
 344 static inline int
 345 setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
 346 {
 347         struct rt_signal_frame __user *sf;
 348         int wsaved, err, sf_size;
 349         void __user *tail;
 350
 351         /* 1. Make sure everything is clean */
 352         synchronize_user_stack();
 353         save_and_clear_fpu();
 354
 355         wsaved = get_thread_wsaved();
 356
 357         sf_size = sizeof(struct rt_signal_frame);
 358         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
 359                 sf_size += sizeof(__siginfo_fpu_t);
 360         if (wsaved)
 361                 sf_size += sizeof(__siginfo_rwin_t);
 362         sf = (struct rt_signal_frame __user *)
 363                 get_sigframe(ksig, regs, sf_size);
 364
 365         if (invalid_frame_pointer (sf)) {
 366                 do_exit(SIGILL);        /* won't return, actually */
 367                 return -EINVAL;
 368         }
 369
 370         tail = (sf + 1);
 371
 372         /* 2. Save the current process state */
 373         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 374
 375         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 376                 __siginfo_fpu_t __user *fpu_save = tail;
 377                 tail += sizeof(__siginfo_fpu_t);
 378                 err |= save_fpu_state(regs, fpu_save);
 379                 err |= __put_user((u64)fpu_save, &sf->fpu_save);
 380         } else {
 381                 err |= __put_user(0, &sf->fpu_save);
 382         }
 383         if (wsaved) {
 384                 __siginfo_rwin_t __user *rwin_save = tail;
 385                 tail += sizeof(__siginfo_rwin_t);
 386                 err |= save_rwin_state(wsaved, rwin_save);
 387                 err |= __put_user((u64)rwin_save, &sf->rwin_save);
 388                 set_thread_wsaved(0);
 389         } else {
 390                 err |= __put_user(0, &sf->rwin_save);
 391         }
 392
 393         /* Setup sigaltstack */
 394         err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
 395
 396         err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
 397
 398         if (!wsaved) {
 399                 err |= copy_in_user((u64 __user *)sf,
 400                                     (u64 __user *)(regs->u_regs[UREG_FP] +
 401                                                    STACK_BIAS),
 402                                     sizeof(struct reg_window));
 403         } else {
 404                 struct reg_window *rp;
 405
 406                 rp = &current_thread_info()->reg_window[wsaved - 1];
 407                 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
 408         }
 409         if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 410                 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
 411         else {
 412                 err |= __put_user(ksig->sig, &sf->info.si_signo);
 413                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 414         }
 415         if (err)
 416                 return err;
 417
 418         /* 3. signal handler back-trampoline and parameters */
 419         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 420         regs->u_regs[UREG_I0] = ksig->sig;
 421         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 422
 423         /* The sigcontext is passed in this way because of how it
 424          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 425          * for sparc64.  It includes the 128 bytes of siginfo_t.
 426          */
 427         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 428
 429         /* 5. signal handler */
 430         regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
 431         regs->tnpc = (regs->tpc + 4);
 432         if (test_thread_flag(TIF_32BIT)) {
 433                 regs->tpc &= 0xffffffff;
 434                 regs->tnpc &= 0xffffffff;
 435         }
 436         /* 4. return to kernel instructions */
 437         regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
 438         return 0;
 439 }
 440
 441 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 442                                    struct sigaction *sa)
 443 {
 444         switch (regs->u_regs[UREG_I0]) {
 445         case ERESTART_RESTARTBLOCK:
 446         case ERESTARTNOHAND:
 447         no_system_call_restart:
 448                 regs->u_regs[UREG_I0] = EINTR;
 449                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 450                 break;
 451         case ERESTARTSYS:
 452                 if (!(sa->sa_flags & SA_RESTART))
 453                         goto no_system_call_restart;
 454                 /* fallthrough */
 455         case ERESTARTNOINTR:
 456                 regs->u_regs[UREG_I0] = orig_i0;
 457                 regs->tpc -= 4;
 458                 regs->tnpc -= 4;
 459         }
 460 }
 461
 462 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 463  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 464  * mistake.
 465  */
 466 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 467 {
 468         struct ksignal ksig;
 469         int restart_syscall;
 470         bool has_handler;
 471
 472         /* It's a lot of work and synchronization to add a new ptrace
 473          * register for GDB to save and restore in order to get
 474          * orig_i0 correct for syscall restarts when debugging.
 475          *
 476          * Although it should be the case that most of the global
 477          * registers are volatile across a system call, glibc already
 478          * depends upon that fact that we preserve them.  So we can't
 479          * just use any global register to save away the orig_i0 value.
 480          *
 481          * In particular %g2, %g3, %g4, and %g5 are all assumed to be
 482          * preserved across a system call trap by various pieces of
 483          * code in glibc.
 484          *
 485          * %g7 is used as the "thread register".   %g6 is not used in
 486          * any fixed manner.  %g6 is used as a scratch register and
 487          * a compiler temporary, but it's value is never used across
 488          * a system call.  Therefore %g6 is usable for orig_i0 storage.
 489          */
 490         if (pt_regs_is_syscall(regs) &&
 491             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
 492                 regs->u_regs[UREG_G6] = orig_i0;
 493
 494 #ifdef CONFIG_COMPAT
 495         if (test_thread_flag(TIF_32BIT)) {
 496                 do_signal32(regs);
 497                 return;
 498         }
 499 #endif
 500
 501         has_handler = get_signal(&ksig);
 502
 503         restart_syscall = 0;
 504         if (pt_regs_is_syscall(regs) &&
 505             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
 506                 restart_syscall = 1;
 507                 orig_i0 = regs->u_regs[UREG_G6];
 508         }
 509
 510         if (has_handler) {
 511                 if (restart_syscall)
 512                         syscall_restart(orig_i0, regs, &ksig.ka.sa);
 513                 signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
 514         } else {
 515                 if (restart_syscall) {
 516                         switch (regs->u_regs[UREG_I0]) {
 517                         case ERESTARTNOHAND:
 518                         case ERESTARTSYS:
 519                         case ERESTARTNOINTR:
 520                                 /* replay the system call when we are done */
 521                                 regs->u_regs[UREG_I0] = orig_i0;
 522                                 regs->tpc -= 4;
 523                                 regs->tnpc -= 4;
 524                                 pt_regs_clear_syscall(regs);
 525                         case ERESTART_RESTARTBLOCK:
 526                                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 527                                 regs->tpc -= 4;
 528                                 regs->tnpc -= 4;
 529                                 pt_regs_clear_syscall(regs);
 530                         }
 531                 }
 532                 restore_saved_sigmask();
 533         }
 534 }
 535
 536 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 537 {
 538         user_exit();
 539         if (thread_info_flags & _TIF_SIGPENDING)
 540                 do_signal(regs, orig_i0);
 541         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 542                 clear_thread_flag(TIF_NOTIFY_RESUME);
 543                 tracehook_notify_resume(regs);
 544         }
 545         user_enter();
 546 }
 547