arch/sparc/kernel/signal_64.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
  27 #include <asm/uaccess.h>
  28 #include <asm/ptrace.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 #include "entry.h"
  36 #include "systbls.h"
  37
  38 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  39
  40 /* {set, get}context() needed for 64-bit SparcLinux userland. */
  41 asmlinkage void sparc64_set_context(struct pt_regs *regs)
  42 {
  43         struct ucontext __user *ucp = (struct ucontext __user *)
  44                 regs->u_regs[UREG_I0];
  45         mc_gregset_t __user *grp;
  46         unsigned long pc, npc, tstate;
  47         unsigned long fp, i7;
  48         unsigned char fenab;
  49         int err;
  50
  51         flush_user_windows();
  52         if (get_thread_wsaved()                                 ||
  53             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
  54             (!__access_ok(ucp, sizeof(*ucp))))
  55                 goto do_sigsegv;
  56         grp  = &ucp->uc_mcontext.mc_gregs;
  57         err  = __get_user(pc, &((*grp)[MC_PC]));
  58         err |= __get_user(npc, &((*grp)[MC_NPC]));
  59         if (err || ((pc | npc) & 3))
  60                 goto do_sigsegv;
  61         if (regs->u_regs[UREG_I1]) {
  62                 sigset_t set;
  63
  64                 if (_NSIG_WORDS == 1) {
  65                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
  66                                 goto do_sigsegv;
  67                 } else {
  68                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
  69                                 goto do_sigsegv;
  70                 }
  71                 sigdelsetmask(&set, ~_BLOCKABLE);
  72                 spin_lock_irq(&current->sighand->siglock);
  73                 current->blocked = set;
  74                 recalc_sigpending();
  75                 spin_unlock_irq(&current->sighand->siglock);
  76         }
  77         if (test_thread_flag(TIF_32BIT)) {
  78                 pc &= 0xffffffff;
  79                 npc &= 0xffffffff;
  80         }
  81         regs->tpc = pc;
  82         regs->tnpc = npc;
  83         err |= __get_user(regs->y, &((*grp)[MC_Y]));
  84         err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
  85         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
  86         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
  87         err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
  88         err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
  89         err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
  90         err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
  91         err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
  92         err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
  93
  94         /* Skip %g7 as that's the thread register in userspace.  */
  95
  96         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
  97         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
  98         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
  99         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
 100         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
 101         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
 102         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
 103         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
 104
 105         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
 106         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
 107         err |= __put_user(fp,
 108               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 109         err |= __put_user(i7,
 110               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 111
 112         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
 113         if (fenab) {
 114                 unsigned long *fpregs = current_thread_info()->fpregs;
 115                 unsigned long fprs;
 116
 117                 fprs_write(0);
 118                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
 119                 if (fprs & FPRS_DL)
 120                         err |= copy_from_user(fpregs,
 121                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
 122                                               (sizeof(unsigned int) * 32));
 123                 if (fprs & FPRS_DU)
 124                         err |= copy_from_user(fpregs+16,
 125                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
 126                          (sizeof(unsigned int) * 32));
 127                 err |= __get_user(current_thread_info()->xfsr[0],
 128                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
 129                 err |= __get_user(current_thread_info()->gsr[0],
 130                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
 131                 regs->tstate &= ~TSTATE_PEF;
 132         }
 133         if (err)
 134                 goto do_sigsegv;
 135
 136         return;
 137 do_sigsegv:
 138         force_sig(SIGSEGV, current);
 139 }
 140
 141 asmlinkage void sparc64_get_context(struct pt_regs *regs)
 142 {
 143         struct ucontext __user *ucp = (struct ucontext __user *)
 144                 regs->u_regs[UREG_I0];
 145         mc_gregset_t __user *grp;
 146         mcontext_t __user *mcp;
 147         unsigned long fp, i7;
 148         unsigned char fenab;
 149         int err;
 150
 151         synchronize_user_stack();
 152         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
 153                 goto do_sigsegv;
 154
 155 #if 1
 156         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
 157 #else
 158         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
 159 #endif
 160
 161         mcp = &ucp->uc_mcontext;
 162         grp = &mcp->mc_gregs;
 163
 164         /* Skip over the trap instruction, first. */
 165         if (test_thread_flag(TIF_32BIT)) {
 166                 regs->tpc   = (regs->tnpc & 0xffffffff);
 167                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
 168         } else {
 169                 regs->tpc   = regs->tnpc;
 170                 regs->tnpc += 4;
 171         }
 172         err = 0;
 173         if (_NSIG_WORDS == 1)
 174                 err |= __put_user(current->blocked.sig[0],
 175                                   (unsigned long __user *)&ucp->uc_sigmask);
 176         else
 177                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
 178                                       sizeof(sigset_t));
 179
 180         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
 181         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
 182         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
 183         err |= __put_user(regs->y, &((*grp)[MC_Y]));
 184         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
 185         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
 186         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
 187         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
 188         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
 189         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
 190         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
 191         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
 192         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
 193         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
 194         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
 195         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
 196         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
 197         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
 198         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
 199
 200         err |= __get_user(fp,
 201                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
 202         err |= __get_user(i7,
 203                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
 204         err |= __put_user(fp, &(mcp->mc_fp));
 205         err |= __put_user(i7, &(mcp->mc_i7));
 206
 207         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
 208         if (fenab) {
 209                 unsigned long *fpregs = current_thread_info()->fpregs;
 210                 unsigned long fprs;
 211
 212                 fprs = current_thread_info()->fpsaved[0];
 213                 if (fprs & FPRS_DL)
 214                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
 215                                             (sizeof(unsigned int) * 32));
 216                 if (fprs & FPRS_DU)
 217                         err |= copy_to_user(
 218                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
 219                           (sizeof(unsigned int) * 32));
 220                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
 221                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
 222                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
 223         }
 224         if (err)
 225                 goto do_sigsegv;
 226
 227         return;
 228 do_sigsegv:
 229         force_sig(SIGSEGV, current);
 230 }
 231
 232 struct rt_signal_frame {
 233         struct sparc_stackf     ss;
 234         siginfo_t               info;
 235         struct pt_regs          regs;
 236         __siginfo_fpu_t __user  *fpu_save;
 237         stack_t                 stack;
 238         sigset_t                mask;
 239         __siginfo_fpu_t         fpu_state;
 240 };
 241
 242 static long _sigpause_common(old_sigset_t set)
 243 {
 244         set &= _BLOCKABLE;
 245         spin_lock_irq(&current->sighand->siglock);
 246         current->saved_sigmask = current->blocked;
 247         siginitset(&current->blocked, set);
 248         recalc_sigpending();
 249         spin_unlock_irq(&current->sighand->siglock);
 250
 251         current->state = TASK_INTERRUPTIBLE;
 252         schedule();
 253
 254         set_restore_sigmask();
 255
 256         return -ERESTARTNOHAND;
 257 }
 258
 259 asmlinkage long sys_sigpause(unsigned int set)
 260 {
 261         return _sigpause_common(set);
 262 }
 263
 264 asmlinkage long sys_sigsuspend(old_sigset_t set)
 265 {
 266         return _sigpause_common(set);
 267 }
 268
 269 static inline int
 270 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 271 {
 272         unsigned long *fpregs = current_thread_info()->fpregs;
 273         unsigned long fprs;
 274         int err;
 275
 276         err = __get_user(fprs, &fpu->si_fprs);
 277         fprs_write(0);
 278         regs->tstate &= ~TSTATE_PEF;
 279         if (fprs & FPRS_DL)
 280                 err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
 281                                (sizeof(unsigned int) * 32));
 282         if (fprs & FPRS_DU)
 283                 err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
 284                                (sizeof(unsigned int) * 32));
 285         err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 286         err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 287         current_thread_info()->fpsaved[0] |= fprs;
 288         return err;
 289 }
 290
 291 void do_rt_sigreturn(struct pt_regs *regs)
 292 {
 293         struct rt_signal_frame __user *sf;
 294         unsigned long tpc, tnpc, tstate;
 295         __siginfo_fpu_t __user *fpu_save;
 296         sigset_t set;
 297         int err;
 298
 299         /* Always make any pending restarted system calls return -EINTR */
 300         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 301
 302         synchronize_user_stack ();
 303         sf = (struct rt_signal_frame __user *)
 304                 (regs->u_regs [UREG_FP] + STACK_BIAS);
 305
 306         /* 1. Make sure we are not getting garbage from the user */
 307         if (((unsigned long) sf) & 3)
 308                 goto segv;
 309
 310         err = get_user(tpc, &sf->regs.tpc);
 311         err |= __get_user(tnpc, &sf->regs.tnpc);
 312         if (test_thread_flag(TIF_32BIT)) {
 313                 tpc &= 0xffffffff;
 314                 tnpc &= 0xffffffff;
 315         }
 316         err |= ((tpc | tnpc) & 3);
 317
 318         /* 2. Restore the state */
 319         err |= __get_user(regs->y, &sf->regs.y);
 320         err |= __get_user(tstate, &sf->regs.tstate);
 321         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
 322
 323         /* User can only change condition codes and %asi in %tstate. */
 324         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 325         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 326
 327         err |= __get_user(fpu_save, &sf->fpu_save);
 328         if (fpu_save)
 329                 err |= restore_fpu_state(regs, &sf->fpu_state);
 330
 331         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 332         err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
 333
 334         if (err)
 335                 goto segv;
 336
 337         regs->tpc = tpc;
 338         regs->tnpc = tnpc;
 339
 340         /* Prevent syscall restart.  */
 341         pt_regs_clear_syscall(regs);
 342
 343         sigdelsetmask(&set, ~_BLOCKABLE);
 344         spin_lock_irq(&current->sighand->siglock);
 345         current->blocked = set;
 346         recalc_sigpending();
 347         spin_unlock_irq(&current->sighand->siglock);
 348         return;
 349 segv:
 350         force_sig(SIGSEGV, current);
 351 }
 352
 353 /* Checks if the fp is valid */
 354 static int invalid_frame_pointer(void __user *fp, int fplen)
 355 {
 356         if (((unsigned long) fp) & 15)
 357                 return 1;
 358         return 0;
 359 }
 360
 361 static inline int
 362 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 363 {
 364         unsigned long *fpregs = current_thread_info()->fpregs;
 365         unsigned long fprs;
 366         int err = 0;
 367
 368         fprs = current_thread_info()->fpsaved[0];
 369         if (fprs & FPRS_DL)
 370                 err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
 371                                     (sizeof(unsigned int) * 32));
 372         if (fprs & FPRS_DU)
 373                 err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
 374                                     (sizeof(unsigned int) * 32));
 375         err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
 376         err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
 377         err |= __put_user(fprs, &fpu->si_fprs);
 378
 379         return err;
 380 }
 381
 382 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
 383 {
 384         unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
 385
 386         /*
 387          * If we are on the alternate signal stack and would overflow it, don't.
 388          * Return an always-bogus address instead so we will die with SIGSEGV.
 389          */
 390         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 391                 return (void __user *) -1L;
 392
 393         /* This is the X/Open sanctioned signal stack switching.  */
 394         if (ka->sa.sa_flags & SA_ONSTACK) {
 395                 if (sas_ss_flags(sp) == 0)
 396                         sp = current->sas_ss_sp + current->sas_ss_size;
 397         }
 398
 399         sp -= framesize;
 400
 401         /* Always align the stack frame.  This handles two cases.  First,
 402          * sigaltstack need not be mindful of platform specific stack
 403          * alignment.  Second, if we took this signal because the stack
 404          * is not aligned properly, we'd like to take the signal cleanly
 405          * and report that.
 406          */
 407         sp &= ~15UL;
 408
 409         return (void __user *) sp;
 410 }
 411
 412 static inline int
 413 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 414                int signo, sigset_t *oldset, siginfo_t *info)
 415 {
 416         struct rt_signal_frame __user *sf;
 417         int sigframe_size, err;
 418
 419         /* 1. Make sure everything is clean */
 420         synchronize_user_stack();
 421         save_and_clear_fpu();
 422
 423         sigframe_size = sizeof(struct rt_signal_frame);
 424         if (!(current_thread_info()->fpsaved[0] & FPRS_FEF))
 425                 sigframe_size -= sizeof(__siginfo_fpu_t);
 426
 427         sf = (struct rt_signal_frame __user *)
 428                 get_sigframe(ka, regs, sigframe_size);
 429
 430         if (invalid_frame_pointer (sf, sigframe_size))
 431                 goto sigill;
 432
 433         if (get_thread_wsaved() != 0)
 434                 goto sigill;
 435
 436         /* 2. Save the current process state */
 437         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
 438
 439         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
 440                 err |= save_fpu_state(regs, &sf->fpu_state);
 441                 err |= __put_user((u64)&sf->fpu_state, &sf->fpu_save);
 442         } else {
 443                 err |= __put_user(0, &sf->fpu_save);
 444         }
 445
 446         /* Setup sigaltstack */
 447         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 448         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 449         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 450
 451         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
 452
 453         err |= copy_in_user((u64 __user *)sf,
 454                             (u64 __user *)(regs->u_regs[UREG_FP]+STACK_BIAS),
 455                             sizeof(struct reg_window));
 456
 457         if (info)
 458                 err |= copy_siginfo_to_user(&sf->info, info);
 459         else {
 460                 err |= __put_user(signo, &sf->info.si_signo);
 461                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
 462         }
 463         if (err)
 464                 goto sigsegv;
 465
 466         /* 3. signal handler back-trampoline and parameters */
 467         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
 468         regs->u_regs[UREG_I0] = signo;
 469         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 470
 471         /* The sigcontext is passed in this way because of how it
 472          * is defined in GLIBC's /usr/include/bits/sigcontext.h
 473          * for sparc64.  It includes the 128 bytes of siginfo_t.
 474          */
 475         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 476
 477         /* 5. signal handler */
 478         regs->tpc = (unsigned long) ka->sa.sa_handler;
 479         regs->tnpc = (regs->tpc + 4);
 480         if (test_thread_flag(TIF_32BIT)) {
 481                 regs->tpc &= 0xffffffff;
 482                 regs->tnpc &= 0xffffffff;
 483         }
 484         /* 4. return to kernel instructions */
 485         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 486         return 0;
 487
 488 sigill:
 489         do_exit(SIGILL);
 490         return -EINVAL;
 491
 492 sigsegv:
 493         force_sigsegv(signo, current);
 494         return -EFAULT;
 495 }
 496
 497 static inline int handle_signal(unsigned long signr, struct k_sigaction *ka,
 498                                 siginfo_t *info,
 499                                 sigset_t *oldset, struct pt_regs *regs)
 500 {
 501         int err;
 502
 503         err = setup_rt_frame(ka, regs, signr, oldset,
 504                              (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
 505         if (err)
 506                 return err;
 507         spin_lock_irq(&current->sighand->siglock);
 508         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 509         if (!(ka->sa.sa_flags & SA_NOMASK))
 510                 sigaddset(&current->blocked,signr);
 511         recalc_sigpending();
 512         spin_unlock_irq(&current->sighand->siglock);
 513
 514         tracehook_signal_handler(signr, info, ka, regs, 0);
 515
 516         return 0;
 517 }
 518
 519 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 520                                    struct sigaction *sa)
 521 {
 522         switch (regs->u_regs[UREG_I0]) {
 523         case ERESTART_RESTARTBLOCK:
 524         case ERESTARTNOHAND:
 525         no_system_call_restart:
 526                 regs->u_regs[UREG_I0] = EINTR;
 527                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
 528                 break;
 529         case ERESTARTSYS:
 530                 if (!(sa->sa_flags & SA_RESTART))
 531                         goto no_system_call_restart;
 532                 /* fallthrough */
 533         case ERESTARTNOINTR:
 534                 regs->u_regs[UREG_I0] = orig_i0;
 535                 regs->tpc -= 4;
 536                 regs->tnpc -= 4;
 537         }
 538 }
 539
 540 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 541  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 542  * mistake.
 543  */
 544 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 545 {
 546         struct k_sigaction ka;
 547         int restart_syscall;
 548         sigset_t *oldset;
 549         siginfo_t info;
 550         int signr;
 551
 552         if (pt_regs_is_syscall(regs) &&
 553             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
 554                 restart_syscall = 1;
 555         } else
 556                 restart_syscall = 0;
 557
 558         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
 559                 oldset = &current->saved_sigmask;
 560         else
 561                 oldset = &current->blocked;
 562
 563 #ifdef CONFIG_COMPAT
 564         if (test_thread_flag(TIF_32BIT)) {
 565                 extern void do_signal32(sigset_t *, struct pt_regs *,
 566                                         int restart_syscall,
 567                                         unsigned long orig_i0);
 568                 do_signal32(oldset, regs, restart_syscall, orig_i0);
 569                 return;
 570         }
 571 #endif
 572
 573         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 574
 575         /* If the debugger messes with the program counter, it clears
 576          * the software "in syscall" bit, directing us to not perform
 577          * a syscall restart.
 578          */
 579         if (restart_syscall && !pt_regs_is_syscall(regs))
 580                 restart_syscall = 0;
 581
 582         if (signr > 0) {
 583                 if (restart_syscall)
 584                         syscall_restart(orig_i0, regs, &ka.sa);
 585                 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
 586                         /* A signal was successfully delivered; the saved
 587                          * sigmask will have been stored in the signal frame,
 588                          * and will be restored by sigreturn, so we can simply
 589                          * clear the TS_RESTORE_SIGMASK flag.
 590                          */
 591                         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 592                 }
 593                 return;
 594         }
 595         if (restart_syscall &&
 596             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 597              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 598              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 599                 /* replay the system call when we are done */
 600                 regs->u_regs[UREG_I0] = orig_i0;
 601                 regs->tpc -= 4;
 602                 regs->tnpc -= 4;
 603                 pt_regs_clear_syscall(regs);
 604         }
 605         if (restart_syscall &&
 606             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 607                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 608                 regs->tpc -= 4;
 609                 regs->tnpc -= 4;
 610                 pt_regs_clear_syscall(regs);
 611         }
 612
 613         /* If there's no signal to deliver, we just put the saved sigmask
 614          * back
 615          */
 616         if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
 617                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 618                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 619         }
 620 }
 621
 622 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
 623 {
 624         if (thread_info_flags & _TIF_SIGPENDING)
 625                 do_signal(regs, orig_i0);
 626         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 627                 clear_thread_flag(TIF_NOTIFY_RESUME);
 628                 tracehook_notify_resume(regs);
 629                 if (current->replacement_session_keyring)
 630                         key_replace_session_keyring();
 631         }
 632 }
 633