arch/sparc64/kernel/signal.c

   1 /*
   2  *  arch/sparc64/kernel/signal.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
   6  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
   7  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
   8  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   9  */
  10
  11 #ifdef CONFIG_COMPAT
  12 #include <linux/compat.h>       /* for compat_old_sigset_t */
  13 #endif
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/signal.h>
  17 #include <linux/errno.h>
  18 #include <linux/wait.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/tracehook.h>
  21 #include <linux/unistd.h>
  22 #include <linux/mm.h>
  23 #include <linux/tty.h>
  24 #include <linux/binfmts.h>
  25 #include <linux/bitops.h>
  26 #include <linux/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
  95         /* Skip %g7 as that's the thread register in userspace.  */
  96
  97         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
  98         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
  99         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
 100         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
 101         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
 102         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
 103         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
 104         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
 105
 106         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 107         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 108         err |= __put_user(fp,
 109               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 110         err |= __put_user(i7,
 111               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 112
 113         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 114         if (fenab) {
 115                 unsigned long *fpregs = current_thread_info()->fpregs;
 116                 unsigned long fprs;
 117
 118                 fprs_write(0);
 119                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 120                 if (fprs & FPRS_DL)
 121                         err |= copy_from_user(fpregs,
 122                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 123                                               (sizeof(unsigned int) * 32));
 124                 if (fprs & FPRS_DU)
 125                         err |= copy_from_user(fpregs+16,
 126                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 127                          (sizeof(unsigned int) * 32));
 128                 err |= __get_user(current_thread_info()->xfsr[0],
 129                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 130                 err |= __get_user(current_thread_info()->gsr[0],
 131                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 132                 regs->tstate &= ~TSTATE_PEF;
 133         }
 134         if (err)
 135                 goto do_sigsegv;
 136
 137         return;
 138 do_sigsegv:
 139         force_sig(SIGSEGV, current);
 140 }
 141
 142 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 143 {
 144         struct ucontext __user *ucp = (struct ucontext __user *)
 145                 regs->u_regs[UREG_I0];
 146         mc_gregset_t __user *grp;
 147         mcontext_t __user *mcp;
 148         unsigned long fp, i7;
 149         unsigned char fenab;
 150         int err;
 151
 152         synchronize_user_stack();
 153         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 154                 goto do_sigsegv;
 155
 156 #if 1
 157         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 158 #else
 159         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 160 #endif
 161
 162         mcp = &ucp->uc_mcontext;
 163         grp = &mcp->mc_gregs;
 164
 165         /* Skip over the trap instruction, first. */
 166         if (test_thread_flag(TIF_32BIT)) {
 167                 regs->tpc   = (regs->tnpc & 0xffffffff);
 168                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 169         } else {
 170                 regs->tpc   = regs->tnpc;
 171                 regs->tnpc += 4;
 172         }
 173         err = 0;
 174         if (_NSIG_WORDS == 1)
 175                 err |= __put_user(current->blocked.sig[0],
 176                                   (unsigned long __user *)&ucp->uc_sigmask);
 177         else
 178                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 179                                       sizeof(sigset_t));
 180
 181         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 182         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 183         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 184         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 185         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 186         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 187         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 188         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 189         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 190         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 191         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 192         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 193         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 194         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 195         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 196         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 197         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 198         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 199         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 200
 201         err |= __get_user(fp,
 202                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 203         err |= __get_user(i7,
 204                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 205         err |= __put_user(fp, &(mcp->mc_fp));
 206         err |= __put_user(i7, &(mcp->mc_i7));
 207
 208         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 209         if (fenab) {
 210                 unsigned long *fpregs = current_thread_info()->fpregs;
 211                 unsigned long fprs;
 212
 213                 fprs = current_thread_info()->fpsaved[0];
 214                 if (fprs & FPRS_DL)
 215                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 216                                             (sizeof(unsigned int) * 32));
 217                 if (fprs & FPRS_DU)
 218                         err |= copy_to_user(
 219                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 220                           (sizeof(unsigned int) * 32));
 221                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 222                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 223                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 224         }
 225         if (err)
 226                 goto do_sigsegv;
 227
 228         return;
 229 do_sigsegv:
 230         force_sig(SIGSEGV, current);
 231 }
 232
 233 struct rt_signal_frame {
 234         struct sparc_stackf     ss;
 235         siginfo_t               info;
 236         struct pt_regs          regs;
 237         __siginfo_fpu_t __user  *fpu_save;
 238         stack_t                 stack;
 239         sigset_t                mask;
 240         __siginfo_fpu_t         fpu_state;
 241 };
 242
 243 static long _sigpause_common(old_sigset_t set)
 244 {
 245         set &= _BLOCKABLE;
 246         spin_lock_irq(&current->sighand->siglock);
 247         current->saved_sigmask = current->blocked;
 248         siginitset(&current->blocked, set);
 249         recalc_sigpending();
 250         spin_unlock_irq(&current->sighand->siglock);
 251
 252         current->state = TASK_INTERRUPTIBLE;
 253         schedule();
 254
 255         set_restore_sigmask();
 256
 257         return -ERESTARTNOHAND;
 258 }
 259
 260 asmlinkage long sys_sigpause(unsigned int set)
 261 {
 262         return _sigpause_common(set);
 263 }
 264
 265 asmlinkage long sys_sigsuspend(old_sigset_t set)
 266 {
 267         return _sigpause_common(set);
 268 }
 269
 270 static inline int
 271 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 272 {
 273         unsigned long *fpregs = current_thread_info()->fpregs;
 274         unsigned long fprs;
 275         int err;
 276
 277         err = __get_user(fprs, &fpu->si_fprs);
 278         fprs_write(0);
 279         regs->tstate &= ~TSTATE_PEF;
 280         if (fprs & FPRS_DL)
 281                 err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 282                                (sizeof(unsigned int) * 32));
 283         if (fprs & FPRS_DU)
 284                 err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 285                                (sizeof(unsigned int) * 32));
 286         err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 287         err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 288         current_thread_info()->fpsaved[0] |= fprs;
 289         return err;
 290 }
 291
 292 void do_rt_sigreturn(struct pt_regs *regs)
 293 {
 294         struct rt_signal_frame __user *sf;
 295         unsigned long tpc, tnpc, tstate;
 296         __siginfo_fpu_t __user *fpu_save;
 297         sigset_t set;
 298         int err;
 299
 300         /* Always make any pending restarted system calls return -EINTR */
 301         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 302
 303         synchronize_user_stack ();
 304         sf = (struct rt_signal_frame __user *)
 305                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 306
 307         /* 1. Make sure we are not getting garbage from the user */
 308         if (((unsigned long) sf) & 3)
 309                 goto segv;
 310
 311         err = get_user(tpc, &sf->regs.tpc);
 312         err |= __get_user(tnpc, &sf->regs.tnpc);
 313         if (test_thread_flag(TIF_32BIT)) {
 314                 tpc &= 0xffffffff;
 315                 tnpc &= 0xffffffff;
 316         }
 317         err |= ((tpc | tnpc) & 3);
 318
 319         /* 2. Restore the state */
 320         err |= __get_user(regs->y, &sf->regs.y);
 321         err |= __get_user(tstate, &sf->regs.tstate);
 322         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 323
 324         /* User can only change condition codes and %asi in %tstate. */
 325         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 326         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 327
 328         err |= __get_user(fpu_save, &sf->fpu_save);
 329         if (fpu_save)
 330                 err |= restore_fpu_state(regs, &sf->fpu_state);
 331
 332         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 333         err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
 334
 335         if (err)
 336                 goto segv;
 337
 338         regs->tpc = tpc;
 339         regs->tnpc = tnpc;
 340
 341         /* Prevent syscall restart.  */
 342         pt_regs_clear_syscall(regs);
 343
 344         sigdelsetmask(&set, ~_BLOCKABLE);
 345         spin_lock_irq(&current->sighand->siglock);
 346         current->blocked = set;
 347         recalc_sigpending();
 348         spin_unlock_irq(&current->sighand->siglock);
 349         return;
 350 segv:
 351         force_sig(SIGSEGV, current);
 352 }
 353
 354 /* Checks if the fp is valid */
 355 static int invalid_frame_pointer(void __user *fp, int fplen)
 356 {
 357         if (((unsigned long) fp) & 7)
 358                 return 1;
 359         return 0;
 360 }
 361
 362 static inline int
 363 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 364 {
 365         unsigned long *fpregs = current_thread_info()->fpregs;
 366         unsigned long fprs;
 367         int err = 0;
 368
 369         fprs = current_thread_info()->fpsaved[0];
 370         if (fprs & FPRS_DL)
 371                 err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 372                                     (sizeof(unsigned int) * 32));
 373         if (fprs & FPRS_DU)
 374                 err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 375                                     (sizeof(unsigned int) * 32));
 376         err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 377         err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 378         err |= __put_user(fprs, &fpu->si_fprs);
 379
 380         return err;
 381 }
 382
 383 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 384 {
 385         unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 386
 387         /*
 388          * If we are on the alternate signal stack and would overflow it, don't.
 389          * Return an always-bogus address instead so we will die with SIGSEGV.
 390          */
 391         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 392                 return (void __user *) -1L;
 393
 394         /* This is the X/Open sanctioned signal stack switching.  */
 395         if (ka->sa.sa_flags & SA_ONSTACK) {
 396                 if (sas_ss_flags(sp) == 0)
 397                         sp = current->sas_ss_sp + current->sas_ss_size;
 398         }
 399
 400         /* Always align the stack frame.  This handles two cases.  First,
 401          * sigaltstack need not be mindful of platform specific stack
 402          * alignment.  Second, if we took this signal because the stack
 403          * is not aligned properly, we'd like to take the signal cleanly
 404          * and report that.
 405          */
 406         sp &= ~7UL;
 407
 408         return (void __user *)(sp - framesize);
 409 }
 410
 411 static inline void
 412 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 413                int signo, sigset_t *oldset, siginfo_t *info)
 414 {
 415         struct rt_signal_frame __user *sf;
 416         int sigframe_size, err;
 417
 418         /* 1. Make sure everything is clean */
 419         synchronize_user_stack();
 420         save_and_clear_fpu();
 421
 422         sigframe_size = sizeof(struct rt_signal_frame);
 423         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 424                 sigframe_size -= sizeof(__siginfo_fpu_t);
 425
 426         sf = (struct rt_signal_frame __user *)
 427                 get_sigframe(ka, regs, sigframe_size);
 428
 429         if (invalid_frame_pointer (sf, sigframe_size))
 430                 goto sigill;
 431
 432         if (get_thread_wsaved() != 0)
 433                 goto sigill;
 434
 435         /* 2. Save the current process state */
 436         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 437
 438         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 439                 err |= save_fpu_state(regs, &sf->fpu_state);
 440                 err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 441         } else {
 442                 err |= __put_user(0, &sf->fpu_save);
 443         }
 444
 445         /* Setup sigaltstack */
 446         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 447         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 448         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 449
 450         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
 451
 452         err |= copy_in_user((u64 __user *)sf,
 453                             (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 454                             sizeof(struct reg_window));
 455
 456         if (info)
 457                 err |= copy_siginfo_to_user(&sf->info, info);
 458         else {
 459                 err |= __put_user(signo, &sf->info.si_signo);
 460                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 461         }
 462         if (err)
 463                 goto sigsegv;
 464
 465         /* 3. signal handler back-trampoline and parameters */
 466         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 467         regs->u_regs[UREG_I0] = signo;
 468         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 469
 470         /* The sigcontext is passed in this way because of how it
 471          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 472          * for sparc64.  It includes the 128 bytes of siginfo_t.
 473          */
 474         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 475
 476         /* 5. signal handler */
 477         regs->tpc = (unsigned long) ka->sa.sa_handler;
 478         regs->tnpc = (regs->tpc + 4);
 479         if (test_thread_flag(TIF_32BIT)) {
 480                 regs->tpc &= 0xffffffff;
 481                 regs->tnpc &= 0xffffffff;
 482         }
 483         /* 4. return to kernel instructions */
 484         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 485         return;
 486
 487 sigill:
 488         do_exit(SIGILL);
 489 sigsegv:
 490         force_sigsegv(signo, current);
 491 }
 492
 493 static inline void handle_signal(unsigned long signr, struct k_sigaction *ka,
 494                                  siginfo_t *info,
 495                                  sigset_t *oldset, struct pt_regs *regs)
 496 {
 497         setup_rt_frame(ka, regs, signr, oldset,
 498                        (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 499         spin_lock_irq(&current->sighand->siglock);
 500         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 501         if (!(ka->sa.sa_flags & SA_NOMASK))
 502                 sigaddset(&current->blocked,signr);
 503         recalc_sigpending();
 504         spin_unlock_irq(&current->sighand->siglock);
 505 }
 506
 507 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 508                                    struct sigaction *sa)
 509 {
 510         switch (regs->u_regs[UREG_I0]) {
 511         case ERESTART_RESTARTBLOCK:
 512         case ERESTARTNOHAND:
 513         no_system_call_restart:
 514                 regs->u_regs[UREG_I0] = EINTR;
 515                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 516                 break;
 517         case ERESTARTSYS:
 518                 if (!(sa->sa_flags & SA_RESTART))
 519                         goto no_system_call_restart;
 520                 /* fallthrough */
 521         case ERESTARTNOINTR:
 522                 regs->u_regs[UREG_I0] = orig_i0;
 523                 regs->tpc -= 4;
 524                 regs->tnpc -= 4;
 525         }
 526 }
 527
 528 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 529  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 530  * mistake.
 531  */
 532 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 533 {
 534         struct k_sigaction ka;
 535         int restart_syscall;
 536         sigset_t *oldset;
 537         siginfo_t info;
 538         int signr;
 539
 540         if (pt_regs_is_syscall(regs) &&
 541             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
 542                 restart_syscall = 1;
 543         } else
 544                 restart_syscall = 0;
 545
 546         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 547                 oldset = &current->saved_sigmask;
 548         else
 549                 oldset = &current->blocked;
 550
 551 #ifdef CONFIG_COMPAT
 552         if (test_thread_flag(TIF_32BIT)) {
 553                 extern void do_signal32(sigset_t *, struct pt_regs *,
 554                                         int restart_syscall,
 555                                         unsigned long orig_i0);
 556                 do_signal32(oldset, regs, restart_syscall, orig_i0);
 557                 return;
 558         }
 559 #endif
 560
 561         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 562
 563         /* If the debugger messes with the program counter, it clears
 564          * the software "in syscall" bit, directing us to not perform
 565          * a syscall restart.
 566          */
 567         if (restart_syscall && !pt_regs_is_syscall(regs))
 568                 restart_syscall = 0;
 569
 570         if (signr > 0) {
 571                 if (restart_syscall)
 572                         syscall_restart(orig_i0, regs, &ka.sa);
 573                 handle_signal(signr, &ka, &info, oldset, regs);
 574
 575                 /* A signal was successfully delivered; the saved
 576                  * sigmask will have been stored in the signal frame,
 577                  * and will be restored by sigreturn, so we can simply
 578                  * clear the TS_RESTORE_SIGMASK flag.
 579                  */
 580                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 581
 582                 tracehook_signal_handler(signr, &info, &ka, regs, 0);
 583                 return;
 584         }
 585         if (restart_syscall &&
 586             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 587              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 588              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 589                 /* replay the system call when we are done */
 590                 regs->u_regs[UREG_I0] = orig_i0;
 591                 regs->tpc -= 4;
 592                 regs->tnpc -= 4;
 593         }
 594         if (restart_syscall &&
 595             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 596                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 597                 regs->tpc -= 4;
 598                 regs->tnpc -= 4;
 599         }
 600
 601         /* If there's no signal to deliver, we just put the saved sigmask
 602          * back
 603          */
 604         if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
 605                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 606                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 607         }
 608 }
 609
 610 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 611 {
 612         if (thread_info_flags & _TIF_SIGPENDING)
 613                 do_signal(regs, orig_i0);
 614         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 615                 clear_thread_flag(TIF_NOTIFY_RESUME);
 616                 tracehook_notify_resume(regs);
 617         }
 618 }