arch/sparc64/kernel/signal.c

   1 /*  $Id: signal.c,v 1.60 2002/02/09 19:49:31 davem Exp $
   2  *  arch/sparc64/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   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 #include <linux/config.h>
  12 #ifdef CONFIG_SPARC32_COMPAT
  13 #include <linux/compat.h>       /* for compat_old_sigset_t */
  14 #endif
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/signal.h>
  18 #include <linux/errno.h>
  19 #include <linux/wait.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/unistd.h>
  22 #include <linux/mm.h>
  23 #include <linux/tty.h>
  24 #include <linux/smp_lock.h>
  25 #include <linux/binfmts.h>
  26 #include <linux/bitops.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/ptrace.h>
  30 #include <asm/svr4.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/fpumacro.h>
  33 #include <asm/uctx.h>
  34 #include <asm/siginfo.h>
  35 #include <asm/visasm.h>
  36
  37 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  38
  39 /* {set, get}context() needed for 64-bit SparcLinux userland. */
  40 asmlinkage void sparc64_set_context(struct pt_regs *regs)
  41 {
  42         struct ucontext __user *ucp = (struct ucontext __user *)
  43                 regs->u_regs[UREG_I0];
  44         mc_gregset_t __user *grp;
  45         unsigned long pc, npc, tstate;
  46         unsigned long fp, i7;
  47         unsigned char fenab;
  48         int err;
  49
  50         flush_user_windows();
  51         if (get_thread_wsaved()                                 ||
  52             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
  53             (!__access_ok(ucp, sizeof(*ucp))))
  54                 goto do_sigsegv;
  55         grp  = &ucp->uc_mcontext.mc_gregs;
  56         err  = __get_user(pc, &((*grp)[MC_PC]));
  57         err |= __get_user(npc, &((*grp)[MC_NPC]));
  58         if (err || ((pc | npc) & 3))
  59                 goto do_sigsegv;
  60         if (regs->u_regs[UREG_I1]) {
  61                 sigset_t set;
  62
  63                 if (_NSIG_WORDS == 1) {
  64                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
  65                                 goto do_sigsegv;
  66                 } else {
  67                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
  68                                 goto do_sigsegv;
  69                 }
  70                 sigdelsetmask(&set, ~_BLOCKABLE);
  71                 spin_lock_irq(&current->sighand->siglock);
  72                 current->blocked = set;
  73                 recalc_sigpending();
  74                 spin_unlock_irq(&current->sighand->siglock);
  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         err |= __get_user(regs->u_regs[UREG_G7], (&(*grp)[MC_G7]));
  93         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
  94         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
  95         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
  96         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
  97         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
  98         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
  99         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
 100         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
 101
 102         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 103         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 104         err |= __put_user(fp,
 105               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 106         err |= __put_user(i7,
 107               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 108
 109         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 110         if (fenab) {
 111                 unsigned long *fpregs = current_thread_info()->fpregs;
 112                 unsigned long fprs;
 113
 114                 fprs_write(0);
 115                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 116                 if (fprs & FPRS_DL)
 117                         err |= copy_from_user(fpregs,
 118                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 119                                               (sizeof(unsigned int) * 32));
 120                 if (fprs & FPRS_DU)
 121                         err |= copy_from_user(fpregs+16,
 122                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 123                          (sizeof(unsigned int) * 32));
 124                 err |= __get_user(current_thread_info()->xfsr[0],
 125                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 126                 err |= __get_user(current_thread_info()->gsr[0],
 127                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 128                 regs->tstate &= ~TSTATE_PEF;
 129         }
 130         if (err)
 131                 goto do_sigsegv;
 132
 133         return;
 134 do_sigsegv:
 135         force_sig(SIGSEGV, current);
 136 }
 137
 138 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 139 {
 140         struct ucontext __user *ucp = (struct ucontext __user *)
 141                 regs->u_regs[UREG_I0];
 142         mc_gregset_t __user *grp;
 143         mcontext_t __user *mcp;
 144         unsigned long fp, i7;
 145         unsigned char fenab;
 146         int err;
 147
 148         synchronize_user_stack();
 149         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 150                 goto do_sigsegv;
 151
 152 #if 1
 153         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 154 #else
 155         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 156 #endif
 157
 158         mcp = &ucp->uc_mcontext;
 159         grp = &mcp->mc_gregs;
 160
 161         /* Skip over the trap instruction, first. */
 162         if (test_thread_flag(TIF_32BIT)) {
 163                 regs->tpc   = (regs->tnpc & 0xffffffff);
 164                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 165         } else {
 166                 regs->tpc   = regs->tnpc;
 167                 regs->tnpc += 4;
 168         }
 169         err = 0;
 170         if (_NSIG_WORDS == 1)
 171                 err |= __put_user(current->blocked.sig[0],
 172                                   (unsigned long __user *)&ucp->uc_sigmask);
 173         else
 174                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 175                                       sizeof(sigset_t));
 176
 177         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 178         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 179         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 180         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 181         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 182         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 183         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 184         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 185         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 186         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 187         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 188         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 189         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 190         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 191         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 192         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 193         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 194         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 195         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 196
 197         err |= __get_user(fp,
 198                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 199         err |= __get_user(i7,
 200                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 201         err |= __put_user(fp, &(mcp->mc_fp));
 202         err |= __put_user(i7, &(mcp->mc_i7));
 203
 204         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 205         if (fenab) {
 206                 unsigned long *fpregs = current_thread_info()->fpregs;
 207                 unsigned long fprs;
 208
 209                 fprs = current_thread_info()->fpsaved[0];
 210                 if (fprs & FPRS_DL)
 211                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 212                                             (sizeof(unsigned int) * 32));
 213                 if (fprs & FPRS_DU)
 214                         err |= copy_to_user(
 215                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 216                           (sizeof(unsigned int) * 32));
 217                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 218                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 219                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 220         }
 221         if (err)
 222                 goto do_sigsegv;
 223
 224         return;
 225 do_sigsegv:
 226         force_sig(SIGSEGV, current);
 227 }
 228
 229 struct rt_signal_frame {
 230         struct sparc_stackf     ss;
 231         siginfo_t               info;
 232         struct pt_regs          regs;
 233         __siginfo_fpu_t __user  *fpu_save;
 234         stack_t                 stack;
 235         sigset_t                mask;
 236         __siginfo_fpu_t         fpu_state;
 237 };
 238
 239 /* Align macros */
 240 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 241
 242 static long _sigpause_common(old_sigset_t set)
 243 {
 244         set &= _BLOCKABLE;
 245         spin_lock_irq(&current->sighand->siglock);
 246         current->saved_sigmask = current->blocked;
 247         siginitset(&current->blocked, set);
 248         recalc_sigpending();
 249         spin_unlock_irq(&current->sighand->siglock);
 250
 251         current->state = TASK_INTERRUPTIBLE;
 252         schedule();
 253         set_thread_flag(TIF_RESTORE_SIGMASK);
 254         return -ERESTARTNOHAND;
 255 }
 256
 257 asmlinkage long sys_sigpause(unsigned int set)
 258 {
 259         return _sigpause_common(set);
 260 }
 261
 262 asmlinkage long sys_sigsuspend(old_sigset_t set)
 263 {
 264         return _sigpause_common(set);
 265 }
 266
 267 static inline int
 268 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 269 {
 270         unsigned long *fpregs = current_thread_info()->fpregs;
 271         unsigned long fprs;
 272         int err;
 273
 274         err = __get_user(fprs, &fpu->si_fprs);
 275         fprs_write(0);
 276         regs->tstate &= ~TSTATE_PEF;
 277         if (fprs & FPRS_DL)
 278                 err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 279                                (sizeof(unsigned int) * 32));
 280         if (fprs & FPRS_DU)
 281                 err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 282                                (sizeof(unsigned int) * 32));
 283         err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 284         err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 285         current_thread_info()->fpsaved[0] |= fprs;
 286         return err;
 287 }
 288
 289 void do_rt_sigreturn(struct pt_regs *regs)
 290 {
 291         struct rt_signal_frame __user *sf;
 292         unsigned long tpc, tnpc, tstate;
 293         __siginfo_fpu_t __user *fpu_save;
 294         mm_segment_t old_fs;
 295         sigset_t set;
 296         stack_t st;
 297         int err;
 298
 299         /* Always make any pending restarted system calls return -EINTR */
 300         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 301
 302         synchronize_user_stack ();
 303         sf = (struct rt_signal_frame __user *)
 304                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 305
 306         /* 1. Make sure we are not getting garbage from the user */
 307         if (((unsigned long) sf) & 3)
 308                 goto segv;
 309
 310         err = get_user(tpc, &sf->regs.tpc);
 311         err |= __get_user(tnpc, &sf->regs.tnpc);
 312         if (test_thread_flag(TIF_32BIT)) {
 313                 tpc &= 0xffffffff;
 314                 tnpc &= 0xffffffff;
 315         }
 316         err |= ((tpc | tnpc) & 3);
 317
 318         /* 2. Restore the state */
 319         err |= __get_user(regs->y, &sf->regs.y);
 320         err |= __get_user(tstate, &sf->regs.tstate);
 321         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 322
 323         /* User can only change condition codes and %asi in %tstate. */
 324         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 325         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 326
 327         err |= __get_user(fpu_save, &sf->fpu_save);
 328         if (fpu_save)
 329                 err |= restore_fpu_state(regs, &sf->fpu_state);
 330
 331         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 332         err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
 333
 334         if (err)
 335                 goto segv;
 336
 337         regs->tpc = tpc;
 338         regs->tnpc = tnpc;
 339
 340         /* It is more difficult to avoid calling this function than to
 341            call it and ignore errors.  */
 342         old_fs = get_fs();
 343         set_fs(KERNEL_DS);
 344         do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
 345         set_fs(old_fs);
 346
 347         sigdelsetmask(&set, ~_BLOCKABLE);
 348         spin_lock_irq(&current->sighand->siglock);
 349         current->blocked = set;
 350         recalc_sigpending();
 351         spin_unlock_irq(&current->sighand->siglock);
 352         return;
 353 segv:
 354         force_sig(SIGSEGV, current);
 355 }
 356
 357 /* Checks if the fp is valid */
 358 static int invalid_frame_pointer(void __user *fp, int fplen)
 359 {
 360         if (((unsigned long) fp) & 7)
 361                 return 1;
 362         return 0;
 363 }
 364
 365 static inline int
 366 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 367 {
 368         unsigned long *fpregs = (unsigned long *)(regs+1);
 369         unsigned long fprs;
 370         int err = 0;
 371
 372         fprs = current_thread_info()->fpsaved[0];
 373         if (fprs & FPRS_DL)
 374                 err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 375                                     (sizeof(unsigned int) * 32));
 376         if (fprs & FPRS_DU)
 377                 err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 378                                     (sizeof(unsigned int) * 32));
 379         err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 380         err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 381         err |= __put_user(fprs, &fpu->si_fprs);
 382
 383         return err;
 384 }
 385
 386 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 387 {
 388         unsigned long sp;
 389
 390         sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 391
 392         /* This is the X/Open sanctioned signal stack switching.  */
 393         if (ka->sa.sa_flags & SA_ONSTACK) {
 394                 if (!on_sig_stack(sp) &&
 395                     !((current->sas_ss_sp + current->sas_ss_size) & 7))
 396                         sp = current->sas_ss_sp + current->sas_ss_size;
 397         }
 398         return (void __user *)(sp - framesize);
 399 }
 400
 401 static inline void
 402 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 403                int signo, sigset_t *oldset, siginfo_t *info)
 404 {
 405         struct rt_signal_frame __user *sf;
 406         int sigframe_size, err;
 407
 408         /* 1. Make sure everything is clean */
 409         synchronize_user_stack();
 410         save_and_clear_fpu();
 411
 412         sigframe_size = RT_ALIGNEDSZ;
 413         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 414                 sigframe_size -= sizeof(__siginfo_fpu_t);
 415
 416         sf = (struct rt_signal_frame __user *)
 417                 get_sigframe(ka, regs, sigframe_size);
 418
 419         if (invalid_frame_pointer (sf, sigframe_size))
 420                 goto sigill;
 421
 422         if (get_thread_wsaved() != 0)
 423                 goto sigill;
 424
 425         /* 2. Save the current process state */
 426         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 427
 428         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 429                 err |= save_fpu_state(regs, &sf->fpu_state);
 430                 err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 431         } else {
 432                 err |= __put_user(0, &sf->fpu_save);
 433         }
 434
 435         /* Setup sigaltstack */
 436         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 437         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 438         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 439
 440         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
 441
 442         err |= copy_in_user((u64 __user *)sf,
 443                             (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 444                             sizeof(struct reg_window));
 445
 446         if (info)
 447                 err |= copy_siginfo_to_user(&sf->info, info);
 448         else {
 449                 err |= __put_user(signo, &sf->info.si_signo);
 450                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 451         }
 452         if (err)
 453                 goto sigsegv;
 454
 455         /* 3. signal handler back-trampoline and parameters */
 456         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 457         regs->u_regs[UREG_I0] = signo;
 458         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 459
 460         /* The sigcontext is passed in this way because of how it
 461          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 462          * for sparc64.  It includes the 128 bytes of siginfo_t.
 463          */
 464         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 465
 466         /* 5. signal handler */
 467         regs->tpc = (unsigned long) ka->sa.sa_handler;
 468         regs->tnpc = (regs->tpc + 4);
 469         if (test_thread_flag(TIF_32BIT)) {
 470                 regs->tpc &= 0xffffffff;
 471                 regs->tnpc &= 0xffffffff;
 472         }
 473         /* 4. return to kernel instructions */
 474         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 475         return;
 476
 477 sigill:
 478         do_exit(SIGILL);
 479 sigsegv:
 480         force_sigsegv(signo, current);
 481 }
 482
 483 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
 484                                  siginfo_t *info,
 485                                  sigset_t *oldset, struct pt_regs *regs)
 486 {
 487         setup_rt_frame(ka, regs, signr, oldset,
 488                        (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 489         spin_lock_irq(&current->sighand->siglock);
 490         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 491         if (!(ka->sa.sa_flags & SA_NOMASK))
 492                 sigaddset(&current->blocked,signr);
 493         recalc_sigpending();
 494         spin_unlock_irq(&current->sighand->siglock);
 495 }
 496
 497 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 498                                      struct sigaction *sa)
 499 {
 500         switch (regs->u_regs[UREG_I0]) {
 501         case ERESTART_RESTARTBLOCK:
 502         case ERESTARTNOHAND:
 503         no_system_call_restart:
 504                 regs->u_regs[UREG_I0] = EINTR;
 505                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 506                 break;
 507         case ERESTARTSYS:
 508                 if (!(sa->sa_flags & SA_RESTART))
 509                         goto no_system_call_restart;
 510                 /* fallthrough */
 511         case ERESTARTNOINTR:
 512                 regs->u_regs[UREG_I0] = orig_i0;
 513                 regs->tpc -= 4;
 514                 regs->tnpc -= 4;
 515         }
 516 }
 517
 518 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 519  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 520  * mistake.
 521  */
 522 static void do_signal(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall)
 523 {
 524         siginfo_t info;
 525         struct signal_deliver_cookie cookie;
 526         struct k_sigaction ka;
 527         int signr;
 528         sigset_t *oldset;
 529
 530         cookie.restart_syscall = restart_syscall;
 531         cookie.orig_i0 = orig_i0;
 532
 533         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 534                 oldset = &current->saved_sigmask;
 535         else
 536                 oldset = &current->blocked;
 537
 538 #ifdef CONFIG_SPARC32_COMPAT
 539         if (test_thread_flag(TIF_32BIT)) {
 540                 extern void do_signal32(sigset_t *, struct pt_regs *,
 541                                         unsigned long, int);
 542                 do_signal32(oldset, regs, orig_i0,
 543                             cookie.restart_syscall);
 544                 return;
 545         }
 546 #endif
 547
 548         signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
 549         if (signr > 0) {
 550                 if (cookie.restart_syscall)
 551                         syscall_restart(orig_i0, regs, &ka.sa);
 552                 handle_signal(signr, &ka, &info, oldset, regs);
 553
 554                 /* a signal was successfully delivered; the saved
 555                  * sigmask will have been stored in the signal frame,
 556                  * and will be restored by sigreturn, so we can simply
 557                  * clear the TIF_RESTORE_SIGMASK flag.
 558                  */
 559                 if (test_thread_flag(TIF_RESTORE_SIGMASK))
 560                         clear_thread_flag(TIF_RESTORE_SIGMASK);
 561                 return;
 562         }
 563         if (cookie.restart_syscall &&
 564             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 565              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 566              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 567                 /* replay the system call when we are done */
 568                 regs->u_regs[UREG_I0] = cookie.orig_i0;
 569                 regs->tpc -= 4;
 570                 regs->tnpc -= 4;
 571         }
 572         if (cookie.restart_syscall &&
 573             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 574                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 575                 regs->tpc -= 4;
 576                 regs->tnpc -= 4;
 577         }
 578
 579         /* if there's no signal to deliver, we just put the saved sigmask
 580          * back
 581          */
 582         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 583                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 584                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 585         }
 586 }
 587
 588 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
 589                       unsigned long thread_info_flags)
 590 {
 591         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 592                 do_signal(regs, orig_i0, restart_syscall);
 593 }
 594
 595 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
 596 {
 597         struct signal_deliver_cookie *cp = cookie;
 598
 599         if (cp->restart_syscall &&
 600             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 601              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 602              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 603                 /* replay the system call when we are done */
 604                 regs->u_regs[UREG_I0] = cp->orig_i0;
 605                 regs->tpc -= 4;
 606                 regs->tnpc -= 4;
 607                 cp->restart_syscall = 0;
 608         }
 609         if (cp->restart_syscall &&
 610             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 611                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 612                 regs->tpc -= 4;
 613                 regs->tnpc -= 4;
 614                 cp->restart_syscall = 0;
 615         }
 616 }