arch/sparc/kernel/signal.c

   1 /*  linux/arch/sparc/kernel/signal.c
   2  *
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
   6  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
   7  */
   8
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/signal.h>
  12 #include <linux/errno.h>
  13 #include <linux/wait.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/unistd.h>
  16 #include <linux/mm.h>
  17 #include <linux/tty.h>
  18 #include <linux/smp.h>
  19 #include <linux/binfmts.h>      /* do_coredum */
  20 #include <linux/bitops.h>
  21
  22 #include <asm/uaccess.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/cacheflush.h>     /* flush_sig_insns */
  27
  28 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  29
  30 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
  31                    void *fpqueue, unsigned long *fpqdepth);
  32 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
  33
  34 struct signal_frame {
  35         struct sparc_stackf     ss;
  36         __siginfo_t             info;
  37         __siginfo_fpu_t __user  *fpu_save;
  38         unsigned long           insns[2] __attribute__ ((aligned (8)));
  39         unsigned int            extramask[_NSIG_WORDS - 1];
  40         unsigned int            extra_size; /* Should be 0 */
  41         __siginfo_fpu_t         fpu_state;
  42 };
  43
  44 struct rt_signal_frame {
  45         struct sparc_stackf     ss;
  46         siginfo_t               info;
  47         struct pt_regs          regs;
  48         sigset_t                mask;
  49         __siginfo_fpu_t __user  *fpu_save;
  50         unsigned int            insns[2];
  51         stack_t                 stack;
  52         unsigned int            extra_size; /* Should be 0 */
  53         __siginfo_fpu_t         fpu_state;
  54 };
  55
  56 /* Align macros */
  57 #define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
  58 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
  59
  60 static int _sigpause_common(old_sigset_t set)
  61 {
  62         set &= _BLOCKABLE;
  63         spin_lock_irq(&current->sighand->siglock);
  64         current->saved_sigmask = current->blocked;
  65         siginitset(&current->blocked, set);
  66         recalc_sigpending();
  67         spin_unlock_irq(&current->sighand->siglock);
  68
  69         current->state = TASK_INTERRUPTIBLE;
  70         schedule();
  71         set_thread_flag(TIF_RESTORE_SIGMASK);
  72
  73         return -ERESTARTNOHAND;
  74 }
  75
  76 asmlinkage int sys_sigsuspend(old_sigset_t set)
  77 {
  78         return _sigpause_common(set);
  79 }
  80
  81 static inline int
  82 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
  83 {
  84         int err;
  85 #ifdef CONFIG_SMP
  86         if (test_tsk_thread_flag(current, TIF_USEDFPU))
  87                 regs->psr &= ~PSR_EF;
  88 #else
  89         if (current == last_task_used_math) {
  90                 last_task_used_math = NULL;
  91                 regs->psr &= ~PSR_EF;
  92         }
  93 #endif
  94         set_used_math();
  95         clear_tsk_thread_flag(current, TIF_USEDFPU);
  96
  97         if (!access_ok(VERIFY_READ, fpu, sizeof(*fpu)))
  98                 return -EFAULT;
  99
 100         err = __copy_from_user(&current->thread.float_regs[0], &fpu->si_float_regs[0],
 101                                (sizeof(unsigned long) * 32));
 102         err |= __get_user(current->thread.fsr, &fpu->si_fsr);
 103         err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
 104         if (current->thread.fpqdepth != 0)
 105                 err |= __copy_from_user(&current->thread.fpqueue[0],
 106                                         &fpu->si_fpqueue[0],
 107                                         ((sizeof(unsigned long) +
 108                                         (sizeof(unsigned long *)))*16));
 109         return err;
 110 }
 111
 112 asmlinkage void do_sigreturn(struct pt_regs *regs)
 113 {
 114         struct signal_frame __user *sf;
 115         unsigned long up_psr, pc, npc;
 116         sigset_t set;
 117         __siginfo_fpu_t __user *fpu_save;
 118         int err;
 119
 120         /* Always make any pending restarted system calls return -EINTR */
 121         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 122
 123         synchronize_user_stack();
 124
 125         sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
 126
 127         /* 1. Make sure we are not getting garbage from the user */
 128         if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
 129                 goto segv_and_exit;
 130
 131         if (((unsigned long) sf) & 3)
 132                 goto segv_and_exit;
 133
 134         err = __get_user(pc,  &sf->info.si_regs.pc);
 135         err |= __get_user(npc, &sf->info.si_regs.npc);
 136
 137         if ((pc | npc) & 3)
 138                 goto segv_and_exit;
 139
 140         /* 2. Restore the state */
 141         up_psr = regs->psr;
 142         err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
 143
 144         /* User can only change condition codes and FPU enabling in %psr. */
 145         regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
 146                   | (regs->psr & (PSR_ICC | PSR_EF));
 147
 148         err |= __get_user(fpu_save, &sf->fpu_save);
 149
 150         if (fpu_save)
 151                 err |= restore_fpu_state(regs, fpu_save);
 152
 153         /* This is pretty much atomic, no amount locking would prevent
 154          * the races which exist anyways.
 155          */
 156         err |= __get_user(set.sig[0], &sf->info.si_mask);
 157         err |= __copy_from_user(&set.sig[1], &sf->extramask,
 158                                 (_NSIG_WORDS-1) * sizeof(unsigned int));
 159
 160         if (err)
 161                 goto segv_and_exit;
 162
 163         sigdelsetmask(&set, ~_BLOCKABLE);
 164         spin_lock_irq(&current->sighand->siglock);
 165         current->blocked = set;
 166         recalc_sigpending();
 167         spin_unlock_irq(&current->sighand->siglock);
 168         return;
 169
 170 segv_and_exit:
 171         force_sig(SIGSEGV, current);
 172 }
 173
 174 asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 175 {
 176         struct rt_signal_frame __user *sf;
 177         unsigned int psr, pc, npc;
 178         __siginfo_fpu_t __user *fpu_save;
 179         mm_segment_t old_fs;
 180         sigset_t set;
 181         stack_t st;
 182         int err;
 183
 184         synchronize_user_stack();
 185         sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
 186         if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
 187             (((unsigned long) sf) & 0x03))
 188                 goto segv;
 189
 190         err = __get_user(pc, &sf->regs.pc);
 191         err |= __get_user(npc, &sf->regs.npc);
 192         err |= ((pc | npc) & 0x03);
 193
 194         err |= __get_user(regs->y, &sf->regs.y);
 195         err |= __get_user(psr, &sf->regs.psr);
 196
 197         err |= __copy_from_user(&regs->u_regs[UREG_G1],
 198                                 &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
 199
 200         regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
 201
 202         err |= __get_user(fpu_save, &sf->fpu_save);
 203
 204         if (fpu_save)
 205                 err |= restore_fpu_state(regs, fpu_save);
 206         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 207
 208         err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
 209
 210         if (err)
 211                 goto segv;
 212
 213         regs->pc = pc;
 214         regs->npc = npc;
 215
 216         /* It is more difficult to avoid calling this function than to
 217          * call it and ignore errors.
 218          */
 219         old_fs = get_fs();
 220         set_fs(KERNEL_DS);
 221         do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
 222         set_fs(old_fs);
 223
 224         sigdelsetmask(&set, ~_BLOCKABLE);
 225         spin_lock_irq(&current->sighand->siglock);
 226         current->blocked = set;
 227         recalc_sigpending();
 228         spin_unlock_irq(&current->sighand->siglock);
 229         return;
 230 segv:
 231         force_sig(SIGSEGV, current);
 232 }
 233
 234 /* Checks if the fp is valid */
 235 static inline int invalid_frame_pointer(void __user *fp, int fplen)
 236 {
 237         if ((((unsigned long) fp) & 7) ||
 238             !__access_ok((unsigned long)fp, fplen) ||
 239             ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&
 240              ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))
 241                 return 1;
 242
 243         return 0;
 244 }
 245
 246 static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
 247 {
 248         unsigned long sp = regs->u_regs[UREG_FP];
 249
 250         /*
 251          * If we are on the alternate signal stack and would overflow it, don't.
 252          * Return an always-bogus address instead so we will die with SIGSEGV.
 253          */
 254         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 255                 return (void __user *) -1L;
 256
 257         /* This is the X/Open sanctioned signal stack switching.  */
 258         if (sa->sa_flags & SA_ONSTACK) {
 259                 if (sas_ss_flags(sp) == 0)
 260                         sp = current->sas_ss_sp + current->sas_ss_size;
 261         }
 262
 263         /* Always align the stack frame.  This handles two cases.  First,
 264          * sigaltstack need not be mindful of platform specific stack
 265          * alignment.  Second, if we took this signal because the stack
 266          * is not aligned properly, we'd like to take the signal cleanly
 267          * and report that.
 268          */
 269         sp &= ~7UL;
 270
 271         return (void __user *)(sp - framesize);
 272 }
 273
 274 static inline int
 275 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 276 {
 277         int err = 0;
 278 #ifdef CONFIG_SMP
 279         if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
 280                 put_psr(get_psr() | PSR_EF);
 281                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 282                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 283                 regs->psr &= ~(PSR_EF);
 284                 clear_tsk_thread_flag(current, TIF_USEDFPU);
 285         }
 286 #else
 287         if (current == last_task_used_math) {
 288                 put_psr(get_psr() | PSR_EF);
 289                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 290                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 291                 last_task_used_math = NULL;
 292                 regs->psr &= ~(PSR_EF);
 293         }
 294 #endif
 295         err |= __copy_to_user(&fpu->si_float_regs[0],
 296                               &current->thread.float_regs[0],
 297                               (sizeof(unsigned long) * 32));
 298         err |= __put_user(current->thread.fsr, &fpu->si_fsr);
 299         err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
 300         if (current->thread.fpqdepth != 0)
 301                 err |= __copy_to_user(&fpu->si_fpqueue[0],
 302                                       &current->thread.fpqueue[0],
 303                                       ((sizeof(unsigned long) +
 304                                       (sizeof(unsigned long *)))*16));
 305         clear_used_math();
 306         return err;
 307 }
 308
 309 static void setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
 310                         int signo, sigset_t *oldset)
 311 {
 312         struct signal_frame __user *sf;
 313         int sigframe_size, err;
 314
 315         /* 1. Make sure everything is clean */
 316         synchronize_user_stack();
 317
 318         sigframe_size = SF_ALIGNEDSZ;
 319         if (!used_math())
 320                 sigframe_size -= sizeof(__siginfo_fpu_t);
 321
 322         sf = (struct signal_frame __user *)
 323                 get_sigframe(&ka->sa, regs, sigframe_size);
 324
 325         if (invalid_frame_pointer(sf, sigframe_size))
 326                 goto sigill_and_return;
 327
 328         if (current_thread_info()->w_saved != 0)
 329                 goto sigill_and_return;
 330
 331         /* 2. Save the current process state */
 332         err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
 333
 334         err |= __put_user(0, &sf->extra_size);
 335
 336         if (used_math()) {
 337                 err |= save_fpu_state(regs, &sf->fpu_state);
 338                 err |= __put_user(&sf->fpu_state, &sf->fpu_save);
 339         } else {
 340                 err |= __put_user(0, &sf->fpu_save);
 341         }
 342
 343         err |= __put_user(oldset->sig[0], &sf->info.si_mask);
 344         err |= __copy_to_user(sf->extramask, &oldset->sig[1],
 345                               (_NSIG_WORDS - 1) * sizeof(unsigned int));
 346         err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 347                               sizeof(struct reg_window));
 348         if (err)
 349                 goto sigsegv;
 350
 351         /* 3. signal handler back-trampoline and parameters */
 352         regs->u_regs[UREG_FP] = (unsigned long) sf;
 353         regs->u_regs[UREG_I0] = signo;
 354         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 355         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 356
 357         /* 4. signal handler */
 358         regs->pc = (unsigned long) ka->sa.sa_handler;
 359         regs->npc = (regs->pc + 4);
 360
 361         /* 5. return to kernel instructions */
 362         if (ka->ka_restorer)
 363                 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 364         else {
 365                 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 366
 367                 /* mov __NR_sigreturn, %g1 */
 368                 err |= __put_user(0x821020d8, &sf->insns[0]);
 369
 370                 /* t 0x10 */
 371                 err |= __put_user(0x91d02010, &sf->insns[1]);
 372                 if (err)
 373                         goto sigsegv;
 374
 375                 /* Flush instruction space. */
 376                 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 377         }
 378         return;
 379
 380 sigill_and_return:
 381         do_exit(SIGILL);
 382 sigsegv:
 383         force_sigsegv(signo, current);
 384 }
 385
 386 static void setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 387                            int signo, sigset_t *oldset, siginfo_t *info)
 388 {
 389         struct rt_signal_frame __user *sf;
 390         int sigframe_size;
 391         unsigned int psr;
 392         int err;
 393
 394         synchronize_user_stack();
 395         sigframe_size = RT_ALIGNEDSZ;
 396         if (!used_math())
 397                 sigframe_size -= sizeof(__siginfo_fpu_t);
 398         sf = (struct rt_signal_frame __user *)
 399                 get_sigframe(&ka->sa, regs, sigframe_size);
 400         if (invalid_frame_pointer(sf, sigframe_size))
 401                 goto sigill;
 402         if (current_thread_info()->w_saved != 0)
 403                 goto sigill;
 404
 405         err  = __put_user(regs->pc, &sf->regs.pc);
 406         err |= __put_user(regs->npc, &sf->regs.npc);
 407         err |= __put_user(regs->y, &sf->regs.y);
 408         psr = regs->psr;
 409         if (used_math())
 410                 psr |= PSR_EF;
 411         err |= __put_user(psr, &sf->regs.psr);
 412         err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
 413         err |= __put_user(0, &sf->extra_size);
 414
 415         if (psr & PSR_EF) {
 416                 err |= save_fpu_state(regs, &sf->fpu_state);
 417                 err |= __put_user(&sf->fpu_state, &sf->fpu_save);
 418         } else {
 419                 err |= __put_user(0, &sf->fpu_save);
 420         }
 421         err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
 422
 423         /* Setup sigaltstack */
 424         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 425         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 426         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 427
 428         err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 429                               sizeof(struct reg_window));
 430
 431         err |= copy_siginfo_to_user(&sf->info, info);
 432
 433         if (err)
 434                 goto sigsegv;
 435
 436         regs->u_regs[UREG_FP] = (unsigned long) sf;
 437         regs->u_regs[UREG_I0] = signo;
 438         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 439         regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
 440
 441         regs->pc = (unsigned long) ka->sa.sa_handler;
 442         regs->npc = (regs->pc + 4);
 443
 444         if (ka->ka_restorer)
 445                 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 446         else {
 447                 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 448
 449                 /* mov __NR_sigreturn, %g1 */
 450                 err |= __put_user(0x821020d8, &sf->insns[0]);
 451
 452                 /* t 0x10 */
 453                 err |= __put_user(0x91d02010, &sf->insns[1]);
 454                 if (err)
 455                         goto sigsegv;
 456
 457                 /* Flush instruction space. */
 458                 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 459         }
 460         return;
 461
 462 sigill:
 463         do_exit(SIGILL);
 464 sigsegv:
 465         force_sigsegv(signo, current);
 466 }
 467
 468 static inline void
 469 handle_signal(unsigned long signr, struct k_sigaction *ka,
 470               siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
 471 {
 472         if (ka->sa.sa_flags & SA_SIGINFO)
 473                 setup_rt_frame(ka, regs, signr, oldset, info);
 474         else
 475                 setup_frame(ka, regs, signr, oldset);
 476
 477         spin_lock_irq(&current->sighand->siglock);
 478         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 479         if (!(ka->sa.sa_flags & SA_NOMASK))
 480                 sigaddset(&current->blocked, signr);
 481         recalc_sigpending();
 482         spin_unlock_irq(&current->sighand->siglock);
 483 }
 484
 485 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 486                                    struct sigaction *sa)
 487 {
 488         switch(regs->u_regs[UREG_I0]) {
 489         case ERESTART_RESTARTBLOCK:
 490         case ERESTARTNOHAND:
 491         no_system_call_restart:
 492                 regs->u_regs[UREG_I0] = EINTR;
 493                 regs->psr |= PSR_C;
 494                 break;
 495         case ERESTARTSYS:
 496                 if (!(sa->sa_flags & SA_RESTART))
 497                         goto no_system_call_restart;
 498                 /* fallthrough */
 499         case ERESTARTNOINTR:
 500                 regs->u_regs[UREG_I0] = orig_i0;
 501                 regs->pc -= 4;
 502                 regs->npc -= 4;
 503         }
 504 }
 505
 506 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 507  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 508  * mistake.
 509  */
 510 asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0, int restart_syscall)
 511 {
 512         siginfo_t info;
 513         struct sparc_deliver_cookie cookie;
 514         struct k_sigaction ka;
 515         int signr;
 516         sigset_t *oldset;
 517
 518         cookie.restart_syscall = restart_syscall;
 519         cookie.orig_i0 = orig_i0;
 520
 521         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 522                 oldset = &current->saved_sigmask;
 523         else
 524                 oldset = &current->blocked;
 525
 526         signr = get_signal_to_deliver(&info, &ka, regs, &cookie);
 527         if (signr > 0) {
 528                 if (cookie.restart_syscall)
 529                         syscall_restart(cookie.orig_i0, regs, &ka.sa);
 530                 handle_signal(signr, &ka, &info, oldset, regs);
 531
 532                 /* a signal was successfully delivered; the saved
 533                  * sigmask will have been stored in the signal frame,
 534                  * and will be restored by sigreturn, so we can simply
 535                  * clear the TIF_RESTORE_SIGMASK flag.
 536                  */
 537                 if (test_thread_flag(TIF_RESTORE_SIGMASK))
 538                         clear_thread_flag(TIF_RESTORE_SIGMASK);
 539                 return;
 540         }
 541         if (cookie.restart_syscall &&
 542             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 543              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 544              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 545                 /* replay the system call when we are done */
 546                 regs->u_regs[UREG_I0] = cookie.orig_i0;
 547                 regs->pc -= 4;
 548                 regs->npc -= 4;
 549         }
 550         if (cookie.restart_syscall &&
 551             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 552                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 553                 regs->pc -= 4;
 554                 regs->npc -= 4;
 555         }
 556
 557         /* if there's no signal to deliver, we just put the saved sigmask
 558          * back
 559          */
 560         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 561                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 562                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 563         }
 564 }
 565
 566 asmlinkage int
 567 do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
 568                 unsigned long sp)
 569 {
 570         int ret = -EFAULT;
 571
 572         /* First see if old state is wanted. */
 573         if (ossptr) {
 574                 if (put_user(current->sas_ss_sp + current->sas_ss_size,
 575                              &ossptr->the_stack) ||
 576                     __put_user(on_sig_stack(sp), &ossptr->cur_status))
 577                         goto out;
 578         }
 579
 580         /* Now see if we want to update the new state. */
 581         if (ssptr) {
 582                 char *ss_sp;
 583
 584                 if (get_user(ss_sp, &ssptr->the_stack))
 585                         goto out;
 586                 /* If the current stack was set with sigaltstack, don't
 587                    swap stacks while we are on it.  */
 588                 ret = -EPERM;
 589                 if (current->sas_ss_sp && on_sig_stack(sp))
 590                         goto out;
 591
 592                 /* Since we don't know the extent of the stack, and we don't
 593                    track onstack-ness, but rather calculate it, we must
 594                    presume a size.  Ho hum this interface is lossy.  */
 595                 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
 596                 current->sas_ss_size = SIGSTKSZ;
 597         }
 598         ret = 0;
 599 out:
 600         return ret;
 601 }
 602
 603 void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
 604 {
 605         struct sparc_deliver_cookie *cp = cookie;
 606
 607         if (cp->restart_syscall &&
 608             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 609              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 610              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 611                 /* replay the system call when we are done */
 612                 regs->u_regs[UREG_I0] = cp->orig_i0;
 613                 regs->pc -= 4;
 614                 regs->npc -= 4;
 615                 cp->restart_syscall = 0;
 616         }
 617
 618         if (cp->restart_syscall &&
 619             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 620                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 621                 regs->pc -= 4;
 622                 regs->npc -= 4;
 623                 cp->restart_syscall = 0;
 624         }
 625 }