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