arch/sparc64/kernel/signal.c

   1 /*
   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_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/tracehook.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
  36 #include "entry.h"
  37 #include "systbls.h"
  38
  39 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  40
  41 /* {set, get}context() needed for 64-bit SparcLinux userland. */
  42 asmlinkage void sparc64_set_context(struct pt_regs *regs)
  43 {
  44         struct ucontext __user *ucp = (struct ucontext __user *)
  45                 regs->u_regs[UREG_I0];
  46         mc_gregset_t __user *grp;
  47         unsigned long pc, npc, tstate;
  48         unsigned long fp, i7;
  49         unsigned char fenab;
  50         int err;
  51
  52         flush_user_windows();
  53         if (get_thread_wsaved()                                 ||
  54             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
  55             (!__access_ok(ucp, sizeof(*ucp))))
  56                 goto do_sigsegv;
  57         grp  = &ucp->uc_mcontext.mc_gregs;
  58         err  = __get_user(pc, &((*grp)[MC_PC]));
  59         err |= __get_user(npc, &((*grp)[MC_NPC]));
  60         if (err || ((pc | npc) & 3))
  61                 goto do_sigsegv;
  62         if (regs->u_regs[UREG_I1]) {
  63                 sigset_t set;
  64
  65                 if (_NSIG_WORDS == 1) {
  66                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
  67                                 goto do_sigsegv;
  68                 } else {
  69                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
  70                                 goto do_sigsegv;
  71                 }
  72                 sigdelsetmask(&set, ~_BLOCKABLE);
  73                 spin_lock_irq(&current->sighand->siglock);
  74                 current->blocked = set;
  75                 recalc_sigpending();
  76                 spin_unlock_irq(&current->sighand->siglock);
  77         }
  78         if (test_thread_flag(TIF_32BIT)) {
  79                 pc &= 0xffffffff;
  80                 npc &= 0xffffffff;
  81         }
  82         regs->tpc = pc;
  83         regs->tnpc = npc;
  84         err |= __get_user(regs->y, &((*grp)[MC_Y]));
  85         err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
  86         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
  87         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
  88         err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
  89         err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
  90         err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
  91         err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
  92         err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
  93         err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
  94         err |= __get_user(regs->u_regs[UREG_G7], (&(*grp)[MC_G7]));
  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
 135         return;
 136 do_sigsegv:
 137         force_sig(SIGSEGV, current);
 138 }
 139
 140 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 141 {
 142         struct ucontext __user *ucp = (struct ucontext __user *)
 143                 regs->u_regs[UREG_I0];
 144         mc_gregset_t __user *grp;
 145         mcontext_t __user *mcp;
 146         unsigned long fp, i7;
 147         unsigned char fenab;
 148         int err;
 149
 150         synchronize_user_stack();
 151         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 152                 goto do_sigsegv;
 153
 154 #if 1
 155         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 156 #else
 157         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 158 #endif
 159
 160         mcp = &ucp->uc_mcontext;
 161         grp = &mcp->mc_gregs;
 162
 163         /* Skip over the trap instruction, first. */
 164         if (test_thread_flag(TIF_32BIT)) {
 165                 regs->tpc   = (regs->tnpc & 0xffffffff);
 166                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 167         } else {
 168                 regs->tpc   = regs->tnpc;
 169                 regs->tnpc += 4;
 170         }
 171         err = 0;
 172         if (_NSIG_WORDS == 1)
 173                 err |= __put_user(current->blocked.sig[0],
 174                                   (unsigned long __user *)&ucp->uc_sigmask);
 175         else
 176                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 177                                       sizeof(sigset_t));
 178
 179         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 180         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 181         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 182         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 183         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 184         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 185         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 186         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 187         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 188         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 189         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 190         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 191         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 192         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 193         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 194         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 195         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 196         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 197         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 198
 199         err |= __get_user(fp,
 200                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 201         err |= __get_user(i7,
 202                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 203         err |= __put_user(fp, &(mcp->mc_fp));
 204         err |= __put_user(i7, &(mcp->mc_i7));
 205
 206         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 207         if (fenab) {
 208                 unsigned long *fpregs = current_thread_info()->fpregs;
 209                 unsigned long fprs;
 210
 211                 fprs = current_thread_info()->fpsaved[0];
 212                 if (fprs & FPRS_DL)
 213                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 214                                             (sizeof(unsigned int) * 32));
 215                 if (fprs & FPRS_DU)
 216                         err |= copy_to_user(
 217                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 218                           (sizeof(unsigned int) * 32));
 219                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 220                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 221                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 222         }
 223         if (err)
 224                 goto do_sigsegv;
 225
 226         return;
 227 do_sigsegv:
 228         force_sig(SIGSEGV, current);
 229 }
 230
 231 struct rt_signal_frame {
 232         struct sparc_stackf     ss;
 233         siginfo_t               info;
 234         struct pt_regs          regs;
 235         __siginfo_fpu_t __user  *fpu_save;
 236         stack_t                 stack;
 237         sigset_t                mask;
 238         __siginfo_fpu_t         fpu_state;
 239 };
 240
 241 static long _sigpause_common(old_sigset_t set)
 242 {
 243         set &= _BLOCKABLE;
 244         spin_lock_irq(&current->sighand->siglock);
 245         current->saved_sigmask = current->blocked;
 246         siginitset(&current->blocked, set);
 247         recalc_sigpending();
 248         spin_unlock_irq(&current->sighand->siglock);
 249
 250         current->state = TASK_INTERRUPTIBLE;
 251         schedule();
 252
 253         set_restore_sigmask();
 254
 255         return -ERESTARTNOHAND;
 256 }
 257
 258 asmlinkage long sys_sigpause(unsigned int set)
 259 {
 260         return _sigpause_common(set);
 261 }
 262
 263 asmlinkage long sys_sigsuspend(old_sigset_t set)
 264 {
 265         return _sigpause_common(set);
 266 }
 267
 268 static inline int
 269 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 270 {
 271         unsigned long *fpregs = current_thread_info()->fpregs;
 272         unsigned long fprs;
 273         int err;
 274
 275         err = __get_user(fprs, &fpu->si_fprs);
 276         fprs_write(0);
 277         regs->tstate &= ~TSTATE_PEF;
 278         if (fprs & FPRS_DL)
 279                 err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 280                                (sizeof(unsigned int) * 32));
 281         if (fprs & FPRS_DU)
 282                 err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 283                                (sizeof(unsigned int) * 32));
 284         err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 285         err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 286         current_thread_info()->fpsaved[0] |= fprs;
 287         return err;
 288 }
 289
 290 void do_rt_sigreturn(struct pt_regs *regs)
 291 {
 292         struct rt_signal_frame __user *sf;
 293         unsigned long tpc, tnpc, tstate;
 294         __siginfo_fpu_t __user *fpu_save;
 295         sigset_t set;
 296         int err;
 297
 298         /* Always make any pending restarted system calls return -EINTR */
 299         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 300
 301         synchronize_user_stack ();
 302         sf = (struct rt_signal_frame __user *)
 303                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 304
 305         /* 1. Make sure we are not getting garbage from the user */
 306         if (((unsigned long) sf) & 3)
 307                 goto segv;
 308
 309         err = get_user(tpc, &sf->regs.tpc);
 310         err |= __get_user(tnpc, &sf->regs.tnpc);
 311         if (test_thread_flag(TIF_32BIT)) {
 312                 tpc &= 0xffffffff;
 313                 tnpc &= 0xffffffff;
 314         }
 315         err |= ((tpc | tnpc) & 3);
 316
 317         /* 2. Restore the state */
 318         err |= __get_user(regs->y, &sf->regs.y);
 319         err |= __get_user(tstate, &sf->regs.tstate);
 320         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 321
 322         /* User can only change condition codes and %asi in %tstate. */
 323         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 324         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 325
 326         err |= __get_user(fpu_save, &sf->fpu_save);
 327         if (fpu_save)
 328                 err |= restore_fpu_state(regs, &sf->fpu_state);
 329
 330         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 331         err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
 332
 333         if (err)
 334                 goto segv;
 335
 336         regs->tpc = tpc;
 337         regs->tnpc = tnpc;
 338
 339         /* Prevent syscall restart.  */
 340         pt_regs_clear_syscall(regs);
 341
 342         sigdelsetmask(&set, ~_BLOCKABLE);
 343         spin_lock_irq(&current->sighand->siglock);
 344         current->blocked = set;
 345         recalc_sigpending();
 346         spin_unlock_irq(&current->sighand->siglock);
 347         return;
 348 segv:
 349         force_sig(SIGSEGV, current);
 350 }
 351
 352 /* Checks if the fp is valid */
 353 static int invalid_frame_pointer(void __user *fp, int fplen)
 354 {
 355         if (((unsigned long) fp) & 7)
 356                 return 1;
 357         return 0;
 358 }
 359
 360 static inline int
 361 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 362 {
 363         unsigned long *fpregs = current_thread_info()->fpregs;
 364         unsigned long fprs;
 365         int err = 0;
 366
 367         fprs = current_thread_info()->fpsaved[0];
 368         if (fprs & FPRS_DL)
 369                 err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 370                                     (sizeof(unsigned int) * 32));
 371         if (fprs & FPRS_DU)
 372                 err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 373                                     (sizeof(unsigned int) * 32));
 374         err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 375         err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 376         err |= __put_user(fprs, &fpu->si_fprs);
 377
 378         return err;
 379 }
 380
 381 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 382 {
 383         unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 384
 385         /*
 386          * If we are on the alternate signal stack and would overflow it, don't.
 387          * Return an always-bogus address instead so we will die with SIGSEGV.
 388          */
 389         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 390                 return (void __user *) -1L;
 391
 392         /* This is the X/Open sanctioned signal stack switching.  */
 393         if (ka->sa.sa_flags & SA_ONSTACK) {
 394                 if (sas_ss_flags(sp) == 0)
 395                         sp = current->sas_ss_sp + current->sas_ss_size;
 396         }
 397
 398         /* Always align the stack frame.  This handles two cases.  First,
 399          * sigaltstack need not be mindful of platform specific stack
 400          * alignment.  Second, if we took this signal because the stack
 401          * is not aligned properly, we'd like to take the signal cleanly
 402          * and report that.
 403          */
 404         sp &= ~7UL;
 405
 406         return (void __user *)(sp - framesize);
 407 }
 408
 409 static inline void
 410 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 411                int signo, sigset_t *oldset, siginfo_t *info)
 412 {
 413         struct rt_signal_frame __user *sf;
 414         int sigframe_size, err;
 415
 416         /* 1. Make sure everything is clean */
 417         synchronize_user_stack();
 418         save_and_clear_fpu();
 419
 420         sigframe_size = sizeof(struct rt_signal_frame);
 421         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 422                 sigframe_size -= sizeof(__siginfo_fpu_t);
 423
 424         sf = (struct rt_signal_frame __user *)
 425                 get_sigframe(ka, regs, sigframe_size);
 426
 427         if (invalid_frame_pointer (sf, sigframe_size))
 428                 goto sigill;
 429
 430         if (get_thread_wsaved() != 0)
 431                 goto sigill;
 432
 433         /* 2. Save the current process state */
 434         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 435
 436         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 437                 err |= save_fpu_state(regs, &sf->fpu_state);
 438                 err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 439         } else {
 440                 err |= __put_user(0, &sf->fpu_save);
 441         }
 442
 443         /* Setup sigaltstack */
 444         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 445         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 446         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 447
 448         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
 449
 450         err |= copy_in_user((u64 __user *)sf,
 451                             (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 452                             sizeof(struct reg_window));
 453
 454         if (info)
 455                 err |= copy_siginfo_to_user(&sf->info, info);
 456         else {
 457                 err |= __put_user(signo, &sf->info.si_signo);
 458                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 459         }
 460         if (err)
 461                 goto sigsegv;
 462
 463         /* 3. signal handler back-trampoline and parameters */
 464         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 465         regs->u_regs[UREG_I0] = signo;
 466         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 467
 468         /* The sigcontext is passed in this way because of how it
 469          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 470          * for sparc64.  It includes the 128 bytes of siginfo_t.
 471          */
 472         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 473
 474         /* 5. signal handler */
 475         regs->tpc = (unsigned long) ka->sa.sa_handler;
 476         regs->tnpc = (regs->tpc + 4);
 477         if (test_thread_flag(TIF_32BIT)) {
 478                 regs->tpc &= 0xffffffff;
 479                 regs->tnpc &= 0xffffffff;
 480         }
 481         /* 4. return to kernel instructions */
 482         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 483         return;
 484
 485 sigill:
 486         do_exit(SIGILL);
 487 sigsegv:
 488         force_sigsegv(signo, current);
 489 }
 490
 491 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
 492                                  siginfo_t *info,
 493                                  sigset_t *oldset, struct pt_regs *regs)
 494 {
 495         setup_rt_frame(ka, regs, signr, oldset,
 496                        (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 497         spin_lock_irq(&current->sighand->siglock);
 498         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 499         if (!(ka->sa.sa_flags & SA_NOMASK))
 500                 sigaddset(&current->blocked,signr);
 501         recalc_sigpending();
 502         spin_unlock_irq(&current->sighand->siglock);
 503 }
 504
 505 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 506                                    struct sigaction *sa)
 507 {
 508         switch (regs->u_regs[UREG_I0]) {
 509         case ERESTART_RESTARTBLOCK:
 510         case ERESTARTNOHAND:
 511         no_system_call_restart:
 512                 regs->u_regs[UREG_I0] = EINTR;
 513                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 514                 break;
 515         case ERESTARTSYS:
 516                 if (!(sa->sa_flags & SA_RESTART))
 517                         goto no_system_call_restart;
 518                 /* fallthrough */
 519         case ERESTARTNOINTR:
 520                 regs->u_regs[UREG_I0] = orig_i0;
 521                 regs->tpc -= 4;
 522                 regs->tnpc -= 4;
 523         }
 524 }
 525
 526 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 527  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 528  * mistake.
 529  */
 530 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 531 {
 532         struct k_sigaction ka;
 533         int restart_syscall;
 534         sigset_t *oldset;
 535         siginfo_t info;
 536         int signr;
 537
 538         if (pt_regs_is_syscall(regs) &&
 539             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
 540                 restart_syscall = 1;
 541         } else
 542                 restart_syscall = 0;
 543
 544         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 545                 oldset = &current->saved_sigmask;
 546         else
 547                 oldset = &current->blocked;
 548
 549 #ifdef CONFIG_COMPAT
 550         if (test_thread_flag(TIF_32BIT)) {
 551                 extern void do_signal32(sigset_t *, struct pt_regs *,
 552                                         int restart_syscall,
 553                                         unsigned long orig_i0);
 554                 do_signal32(oldset, regs, restart_syscall, orig_i0);
 555                 return;
 556         }
 557 #endif
 558
 559         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 560
 561         /* If the debugger messes with the program counter, it clears
 562          * the software "in syscall" bit, directing us to not perform
 563          * a syscall restart.
 564          */
 565         if (restart_syscall && !pt_regs_is_syscall(regs))
 566                 restart_syscall = 0;
 567
 568         if (signr > 0) {
 569                 if (restart_syscall)
 570                         syscall_restart(orig_i0, regs, &ka.sa);
 571                 handle_signal(signr, &ka, &info, oldset, regs);
 572
 573                 /* A signal was successfully delivered; the saved
 574                  * sigmask will have been stored in the signal frame,
 575                  * and will be restored by sigreturn, so we can simply
 576                  * clear the TS_RESTORE_SIGMASK flag.
 577                  */
 578                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 579
 580                 tracehook_signal_handler(signr, &info, &ka, regs, 0);
 581                 return;
 582         }
 583         if (restart_syscall &&
 584             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 585              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 586              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 587                 /* replay the system call when we are done */
 588                 regs->u_regs[UREG_I0] = orig_i0;
 589                 regs->tpc -= 4;
 590                 regs->tnpc -= 4;
 591         }
 592         if (restart_syscall &&
 593             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 594                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 595                 regs->tpc -= 4;
 596                 regs->tnpc -= 4;
 597         }
 598
 599         /* If there's no signal to deliver, we just put the saved sigmask
 600          * back
 601          */
 602         if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
 603                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 604                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 605         }
 606 }
 607
 608 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 609 {
 610         if (thread_info_flags & _TIF_SIGPENDING)
 611                 do_signal(regs, orig_i0);
 612         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 613                 clear_thread_flag(TIF_NOTIFY_RESUME);
 614                 tracehook_notify_resume(regs);
 615         }
 616 }