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 #ifdef CONFIG_SPARC32_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/unistd.h>
  21 #include <linux/mm.h>
  22 #include <linux/tty.h>
  23 #include <linux/binfmts.h>
  24 #include <linux/bitops.h>
  25
  26 #include <asm/uaccess.h>
  27 #include <asm/ptrace.h>
  28 #include <asm/svr4.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/fpumacro.h>
  31 #include <asm/uctx.h>
  32 #include <asm/siginfo.h>
  33 #include <asm/visasm.h>
  34
  35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  36
  37 /* {set, get}context() needed for 64-bit SparcLinux userland. */
  38 asmlinkage void sparc64_set_context(struct pt_regs *regs)
  39 {
  40         struct ucontext __user *ucp = (struct ucontext __user *)
  41                 regs->u_regs[UREG_I0];
  42         mc_gregset_t __user *grp;
  43         unsigned long pc, npc, tstate;
  44         unsigned long fp, i7;
  45         unsigned char fenab;
  46         int err;
  47
  48         flush_user_windows();
  49         if (get_thread_wsaved()                                 ||
  50             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
  51             (!__access_ok(ucp, sizeof(*ucp))))
  52                 goto do_sigsegv;
  53         grp  = &ucp->uc_mcontext.mc_gregs;
  54         err  = __get_user(pc, &((*grp)[MC_PC]));
  55         err |= __get_user(npc, &((*grp)[MC_NPC]));
  56         if (err || ((pc | npc) & 3))
  57                 goto do_sigsegv;
  58         if (regs->u_regs[UREG_I1]) {
  59                 sigset_t set;
  60
  61                 if (_NSIG_WORDS == 1) {
  62                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
  63                                 goto do_sigsegv;
  64                 } else {
  65                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
  66                                 goto do_sigsegv;
  67                 }
  68                 sigdelsetmask(&set, ~_BLOCKABLE);
  69                 spin_lock_irq(&current->sighand->siglock);
  70                 current->blocked = set;
  71                 recalc_sigpending();
  72                 spin_unlock_irq(&current->sighand->siglock);
  73         }
  74         if (test_thread_flag(TIF_32BIT)) {
  75                 pc &= 0xffffffff;
  76                 npc &= 0xffffffff;
  77         }
  78         regs->tpc = pc;
  79         regs->tnpc = npc;
  80         err |= __get_user(regs->y, &((*grp)[MC_Y]));
  81         err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
  82         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
  83         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
  84         err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
  85         err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
  86         err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
  87         err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
  88         err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
  89         err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
  90         err |= __get_user(regs->u_regs[UREG_G7], (&(*grp)[MC_G7]));
  91         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
  92         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
  93         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
  94         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
  95         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
  96         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
  97         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
  98         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
  99
 100         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 101         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 102         err |= __put_user(fp,
 103               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 104         err |= __put_user(i7,
 105               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 106
 107         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 108         if (fenab) {
 109                 unsigned long *fpregs = current_thread_info()->fpregs;
 110                 unsigned long fprs;
 111
 112                 fprs_write(0);
 113                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 114                 if (fprs & FPRS_DL)
 115                         err |= copy_from_user(fpregs,
 116                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 117                                               (sizeof(unsigned int) * 32));
 118                 if (fprs & FPRS_DU)
 119                         err |= copy_from_user(fpregs+16,
 120                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 121                          (sizeof(unsigned int) * 32));
 122                 err |= __get_user(current_thread_info()->xfsr[0],
 123                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 124                 err |= __get_user(current_thread_info()->gsr[0],
 125                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 126                 regs->tstate &= ~TSTATE_PEF;
 127         }
 128         if (err)
 129                 goto do_sigsegv;
 130
 131         return;
 132 do_sigsegv:
 133         force_sig(SIGSEGV, current);
 134 }
 135
 136 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 137 {
 138         struct ucontext __user *ucp = (struct ucontext __user *)
 139                 regs->u_regs[UREG_I0];
 140         mc_gregset_t __user *grp;
 141         mcontext_t __user *mcp;
 142         unsigned long fp, i7;
 143         unsigned char fenab;
 144         int err;
 145
 146         synchronize_user_stack();
 147         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 148                 goto do_sigsegv;
 149
 150 #if 1
 151         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 152 #else
 153         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 154 #endif
 155
 156         mcp = &ucp->uc_mcontext;
 157         grp = &mcp->mc_gregs;
 158
 159         /* Skip over the trap instruction, first. */
 160         if (test_thread_flag(TIF_32BIT)) {
 161                 regs->tpc   = (regs->tnpc & 0xffffffff);
 162                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 163         } else {
 164                 regs->tpc   = regs->tnpc;
 165                 regs->tnpc += 4;
 166         }
 167         err = 0;
 168         if (_NSIG_WORDS == 1)
 169                 err |= __put_user(current->blocked.sig[0],
 170                                   (unsigned long __user *)&ucp->uc_sigmask);
 171         else
 172                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 173                                       sizeof(sigset_t));
 174
 175         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 176         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 177         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 178         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 179         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 180         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 181         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 182         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 183         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 184         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 185         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 186         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 187         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 188         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 189         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 190         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 191         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 192         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 193         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 194
 195         err |= __get_user(fp,
 196                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 197         err |= __get_user(i7,
 198                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 199         err |= __put_user(fp, &(mcp->mc_fp));
 200         err |= __put_user(i7, &(mcp->mc_i7));
 201
 202         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 203         if (fenab) {
 204                 unsigned long *fpregs = current_thread_info()->fpregs;
 205                 unsigned long fprs;
 206
 207                 fprs = current_thread_info()->fpsaved[0];
 208                 if (fprs & FPRS_DL)
 209                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 210                                             (sizeof(unsigned int) * 32));
 211                 if (fprs & FPRS_DU)
 212                         err |= copy_to_user(
 213                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 214                           (sizeof(unsigned int) * 32));
 215                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 216                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 217                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 218         }
 219         if (err)
 220                 goto do_sigsegv;
 221
 222         return;
 223 do_sigsegv:
 224         force_sig(SIGSEGV, current);
 225 }
 226
 227 struct rt_signal_frame {
 228         struct sparc_stackf     ss;
 229         siginfo_t               info;
 230         struct pt_regs          regs;
 231         __siginfo_fpu_t __user  *fpu_save;
 232         stack_t                 stack;
 233         sigset_t                mask;
 234         __siginfo_fpu_t         fpu_state;
 235 };
 236
 237 /* Align macros */
 238 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
 239
 240 static long _sigpause_common(old_sigset_t set)
 241 {
 242         set &= _BLOCKABLE;
 243         spin_lock_irq(&current->sighand->siglock);
 244         current->saved_sigmask = current->blocked;
 245         siginitset(&current->blocked, set);
 246         recalc_sigpending();
 247         spin_unlock_irq(&current->sighand->siglock);
 248
 249         current->state = TASK_INTERRUPTIBLE;
 250         schedule();
 251         set_thread_flag(TIF_RESTORE_SIGMASK);
 252         return -ERESTARTNOHAND;
 253 }
 254
 255 asmlinkage long sys_sigpause(unsigned int set)
 256 {
 257         return _sigpause_common(set);
 258 }
 259
 260 asmlinkage long sys_sigsuspend(old_sigset_t set)
 261 {
 262         return _sigpause_common(set);
 263 }
 264
 265 static inline int
 266 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 267 {
 268         unsigned long *fpregs = current_thread_info()->fpregs;
 269         unsigned long fprs;
 270         int err;
 271
 272         err = __get_user(fprs, &fpu->si_fprs);
 273         fprs_write(0);
 274         regs->tstate &= ~TSTATE_PEF;
 275         if (fprs & FPRS_DL)
 276                 err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 277                                (sizeof(unsigned int) * 32));
 278         if (fprs & FPRS_DU)
 279                 err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 280                                (sizeof(unsigned int) * 32));
 281         err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 282         err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 283         current_thread_info()->fpsaved[0] |= fprs;
 284         return err;
 285 }
 286
 287 void do_rt_sigreturn(struct pt_regs *regs)
 288 {
 289         struct rt_signal_frame __user *sf;
 290         unsigned long tpc, tnpc, tstate;
 291         __siginfo_fpu_t __user *fpu_save;
 292         sigset_t set;
 293         int err;
 294
 295         /* Always make any pending restarted system calls return -EINTR */
 296         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 297
 298         synchronize_user_stack ();
 299         sf = (struct rt_signal_frame __user *)
 300                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 301
 302         /* 1. Make sure we are not getting garbage from the user */
 303         if (((unsigned long) sf) & 3)
 304                 goto segv;
 305
 306         err = get_user(tpc, &sf->regs.tpc);
 307         err |= __get_user(tnpc, &sf->regs.tnpc);
 308         if (test_thread_flag(TIF_32BIT)) {
 309                 tpc &= 0xffffffff;
 310                 tnpc &= 0xffffffff;
 311         }
 312         err |= ((tpc | tnpc) & 3);
 313
 314         /* 2. Restore the state */
 315         err |= __get_user(regs->y, &sf->regs.y);
 316         err |= __get_user(tstate, &sf->regs.tstate);
 317         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 318
 319         /* User can only change condition codes and %asi in %tstate. */
 320         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 321         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 322
 323         err |= __get_user(fpu_save, &sf->fpu_save);
 324         if (fpu_save)
 325                 err |= restore_fpu_state(regs, &sf->fpu_state);
 326
 327         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 328         err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
 329
 330         if (err)
 331                 goto segv;
 332
 333         regs->tpc = tpc;
 334         regs->tnpc = tnpc;
 335
 336         sigdelsetmask(&set, ~_BLOCKABLE);
 337         spin_lock_irq(&current->sighand->siglock);
 338         current->blocked = set;
 339         recalc_sigpending();
 340         spin_unlock_irq(&current->sighand->siglock);
 341         return;
 342 segv:
 343         force_sig(SIGSEGV, current);
 344 }
 345
 346 /* Checks if the fp is valid */
 347 static int invalid_frame_pointer(void __user *fp, int fplen)
 348 {
 349         if (((unsigned long) fp) & 7)
 350                 return 1;
 351         return 0;
 352 }
 353
 354 static inline int
 355 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 356 {
 357         unsigned long *fpregs = (unsigned long *)(regs+1);
 358         unsigned long fprs;
 359         int err = 0;
 360
 361         fprs = current_thread_info()->fpsaved[0];
 362         if (fprs & FPRS_DL)
 363                 err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 364                                     (sizeof(unsigned int) * 32));
 365         if (fprs & FPRS_DU)
 366                 err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 367                                     (sizeof(unsigned int) * 32));
 368         err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 369         err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 370         err |= __put_user(fprs, &fpu->si_fprs);
 371
 372         return err;
 373 }
 374
 375 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 376 {
 377         unsigned long sp;
 378
 379         sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 380
 381         /* This is the X/Open sanctioned signal stack switching.  */
 382         if (ka->sa.sa_flags & SA_ONSTACK) {
 383                 if (!on_sig_stack(sp) &&
 384                     !((current->sas_ss_sp + current->sas_ss_size) & 7))
 385                         sp = current->sas_ss_sp + current->sas_ss_size;
 386         }
 387         return (void __user *)(sp - framesize);
 388 }
 389
 390 static inline void
 391 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 392                int signo, sigset_t *oldset, siginfo_t *info)
 393 {
 394         struct rt_signal_frame __user *sf;
 395         int sigframe_size, err;
 396
 397         /* 1. Make sure everything is clean */
 398         synchronize_user_stack();
 399         save_and_clear_fpu();
 400
 401         sigframe_size = RT_ALIGNEDSZ;
 402         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 403                 sigframe_size -= sizeof(__siginfo_fpu_t);
 404
 405         sf = (struct rt_signal_frame __user *)
 406                 get_sigframe(ka, regs, sigframe_size);
 407
 408         if (invalid_frame_pointer (sf, sigframe_size))
 409                 goto sigill;
 410
 411         if (get_thread_wsaved() != 0)
 412                 goto sigill;
 413
 414         /* 2. Save the current process state */
 415         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 416
 417         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 418                 err |= save_fpu_state(regs, &sf->fpu_state);
 419                 err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 420         } else {
 421                 err |= __put_user(0, &sf->fpu_save);
 422         }
 423
 424         /* Setup sigaltstack */
 425         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 426         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 427         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 428
 429         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
 430
 431         err |= copy_in_user((u64 __user *)sf,
 432                             (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 433                             sizeof(struct reg_window));
 434
 435         if (info)
 436                 err |= copy_siginfo_to_user(&sf->info, info);
 437         else {
 438                 err |= __put_user(signo, &sf->info.si_signo);
 439                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 440         }
 441         if (err)
 442                 goto sigsegv;
 443
 444         /* 3. signal handler back-trampoline and parameters */
 445         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 446         regs->u_regs[UREG_I0] = signo;
 447         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 448
 449         /* The sigcontext is passed in this way because of how it
 450          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 451          * for sparc64.  It includes the 128 bytes of siginfo_t.
 452          */
 453         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 454
 455         /* 5. signal handler */
 456         regs->tpc = (unsigned long) ka->sa.sa_handler;
 457         regs->tnpc = (regs->tpc + 4);
 458         if (test_thread_flag(TIF_32BIT)) {
 459                 regs->tpc &= 0xffffffff;
 460                 regs->tnpc &= 0xffffffff;
 461         }
 462         /* 4. return to kernel instructions */
 463         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 464         return;
 465
 466 sigill:
 467         do_exit(SIGILL);
 468 sigsegv:
 469         force_sigsegv(signo, current);
 470 }
 471
 472 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
 473                                  siginfo_t *info,
 474                                  sigset_t *oldset, struct pt_regs *regs)
 475 {
 476         setup_rt_frame(ka, regs, signr, oldset,
 477                        (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 478         spin_lock_irq(&current->sighand->siglock);
 479         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 480         if (!(ka->sa.sa_flags & SA_NOMASK))
 481                 sigaddset(&current->blocked,signr);
 482         recalc_sigpending();
 483         spin_unlock_irq(&current->sighand->siglock);
 484 }
 485
 486 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 487                                      struct sigaction *sa)
 488 {
 489         switch (regs->u_regs[UREG_I0]) {
 490         case ERESTART_RESTARTBLOCK:
 491         case ERESTARTNOHAND:
 492         no_system_call_restart:
 493                 regs->u_regs[UREG_I0] = EINTR;
 494                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 495                 break;
 496         case ERESTARTSYS:
 497                 if (!(sa->sa_flags & SA_RESTART))
 498                         goto no_system_call_restart;
 499                 /* fallthrough */
 500         case ERESTARTNOINTR:
 501                 regs->u_regs[UREG_I0] = orig_i0;
 502                 regs->tpc -= 4;
 503                 regs->tnpc -= 4;
 504         }
 505 }
 506
 507 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 508  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 509  * mistake.
 510  */
 511 static void do_signal(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall)
 512 {
 513         siginfo_t info;
 514         struct signal_deliver_cookie cookie;
 515         struct k_sigaction ka;
 516         int signr;
 517         sigset_t *oldset;
 518
 519         cookie.restart_syscall = restart_syscall;
 520         cookie.orig_i0 = orig_i0;
 521
 522         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 523                 oldset = &current->saved_sigmask;
 524         else
 525                 oldset = &current->blocked;
 526
 527 #ifdef CONFIG_SPARC32_COMPAT
 528         if (test_thread_flag(TIF_32BIT)) {
 529                 extern void do_signal32(sigset_t *, struct pt_regs *,
 530                                         unsigned long, int);
 531                 do_signal32(oldset, regs, orig_i0,
 532                             cookie.restart_syscall);
 533                 return;
 534         }
 535 #endif
 536
 537         signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
 538         if (signr > 0) {
 539                 if (cookie.restart_syscall)
 540                         syscall_restart(orig_i0, regs, &ka.sa);
 541                 handle_signal(signr, &ka, &info, oldset, regs);
 542
 543                 /* a signal was successfully delivered; the saved
 544                  * sigmask will have been stored in the signal frame,
 545                  * and will be restored by sigreturn, so we can simply
 546                  * clear the TIF_RESTORE_SIGMASK flag.
 547                  */
 548                 if (test_thread_flag(TIF_RESTORE_SIGMASK))
 549                         clear_thread_flag(TIF_RESTORE_SIGMASK);
 550                 return;
 551         }
 552         if (cookie.restart_syscall &&
 553             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 554              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 555              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 556                 /* replay the system call when we are done */
 557                 regs->u_regs[UREG_I0] = cookie.orig_i0;
 558                 regs->tpc -= 4;
 559                 regs->tnpc -= 4;
 560         }
 561         if (cookie.restart_syscall &&
 562             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 563                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 564                 regs->tpc -= 4;
 565                 regs->tnpc -= 4;
 566         }
 567
 568         /* if there's no signal to deliver, we just put the saved sigmask
 569          * back
 570          */
 571         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 572                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 573                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 574         }
 575 }
 576
 577 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, int restart_syscall,
 578                       unsigned long thread_info_flags)
 579 {
 580         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 581                 do_signal(regs, orig_i0, restart_syscall);
 582 }
 583
 584 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
 585 {
 586         struct signal_deliver_cookie *cp = cookie;
 587
 588         if (cp->restart_syscall &&
 589             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 590              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 591              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 592                 /* replay the system call when we are done */
 593                 regs->u_regs[UREG_I0] = cp->orig_i0;
 594                 regs->tpc -= 4;
 595                 regs->tnpc -= 4;
 596                 cp->restart_syscall = 0;
 597         }
 598         if (cp->restart_syscall &&
 599             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 600                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 601                 regs->tpc -= 4;
 602                 regs->tnpc -= 4;
 603                 cp->restart_syscall = 0;
 604         }
 605 }