arch/mips/kernel/signal.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1991, 1992  Linus Torvalds
   7  * Copyright (C) 1994 - 2000  Ralf Baechle
   8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   9  * Copyright (C) 2014, Imagination Technologies Ltd.
  10  */
  11 #include <linux/cache.h>
  12 #include <linux/context_tracking.h>
  13 #include <linux/irqflags.h>
  14 #include <linux/sched.h>
  15 #include <linux/mm.h>
  16 #include <linux/personality.h>
  17 #include <linux/smp.h>
  18 #include <linux/kernel.h>
  19 #include <linux/signal.h>
  20 #include <linux/errno.h>
  21 #include <linux/wait.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/unistd.h>
  24 #include <linux/compiler.h>
  25 #include <linux/syscalls.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/tracehook.h>
  28
  29 #include <asm/abi.h>
  30 #include <asm/asm.h>
  31 #include <linux/bitops.h>
  32 #include <asm/cacheflush.h>
  33 #include <asm/fpu.h>
  34 #include <asm/sim.h>
  35 #include <asm/ucontext.h>
  36 #include <asm/cpu-features.h>
  37 #include <asm/war.h>
  38 #include <asm/vdso.h>
  39 #include <asm/dsp.h>
  40 #include <asm/inst.h>
  41
  42 #include "signal-common.h"
  43
  44 static int (*save_fp_context)(void __user *sc);
  45 static int (*restore_fp_context)(void __user *sc);
  46
  47 struct sigframe {
  48         u32 sf_ass[4];          /* argument save space for o32 */
  49         u32 sf_pad[2];          /* Was: signal trampoline */
  50         struct sigcontext sf_sc;
  51         sigset_t sf_mask;
  52 };
  53
  54 struct rt_sigframe {
  55         u32 rs_ass[4];          /* argument save space for o32 */
  56         u32 rs_pad[2];          /* Was: signal trampoline */
  57         struct siginfo rs_info;
  58         struct ucontext rs_uc;
  59 };
  60
  61 /*
  62  * Thread saved context copy to/from a signal context presumed to be on the
  63  * user stack, and therefore accessed with appropriate macros from uaccess.h.
  64  */
  65 static int copy_fp_to_sigcontext(void __user *sc)
  66 {
  67         struct mips_abi *abi = current->thread.abi;
  68         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
  69         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
  70         int i;
  71         int err = 0;
  72
  73         for (i = 0; i < NUM_FPU_REGS; i++) {
  74                 err |=
  75                     __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
  76                                &fpregs[i]);
  77         }
  78         err |= __put_user(current->thread.fpu.fcr31, csr);
  79
  80         return err;
  81 }
  82
  83 static int copy_fp_from_sigcontext(void __user *sc)
  84 {
  85         struct mips_abi *abi = current->thread.abi;
  86         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
  87         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
  88         int i;
  89         int err = 0;
  90         u64 fpr_val;
  91
  92         for (i = 0; i < NUM_FPU_REGS; i++) {
  93                 err |= __get_user(fpr_val, &fpregs[i]);
  94                 set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
  95         }
  96         err |= __get_user(current->thread.fpu.fcr31, csr);
  97
  98         return err;
  99 }
 100
 101 /*
 102  * Wrappers for the assembly _{save,restore}_fp_context functions.
 103  */
 104 static int save_hw_fp_context(void __user *sc)
 105 {
 106         struct mips_abi *abi = current->thread.abi;
 107         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 108         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 109
 110         return _save_fp_context(fpregs, csr);
 111 }
 112
 113 static int restore_hw_fp_context(void __user *sc)
 114 {
 115         struct mips_abi *abi = current->thread.abi;
 116         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 117         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 118
 119         return _restore_fp_context(fpregs, csr);
 120 }
 121
 122 /*
 123  * Helper routines
 124  */
 125 static int protected_save_fp_context(void __user *sc)
 126 {
 127         struct mips_abi *abi = current->thread.abi;
 128         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 129         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 130         int err;
 131
 132         /*
 133          * EVA does not have userland equivalents of ldc1 or sdc1, so
 134          * save to the kernel FP context & copy that to userland below.
 135          */
 136         if (config_enabled(CONFIG_EVA))
 137                 lose_fpu(1);
 138
 139         while (1) {
 140                 lock_fpu_owner();
 141                 if (is_fpu_owner()) {
 142                         err = save_fp_context(sc);
 143                         unlock_fpu_owner();
 144                 } else {
 145                         unlock_fpu_owner();
 146                         err = copy_fp_to_sigcontext(sc);
 147                 }
 148                 if (likely(!err))
 149                         break;
 150                 /* touch the sigcontext and try again */
 151                 err = __put_user(0, &fpregs[0]) |
 152                         __put_user(0, &fpregs[31]) |
 153                         __put_user(0, csr);
 154                 if (err)
 155                         break;  /* really bad sigcontext */
 156         }
 157
 158         return err;
 159 }
 160
 161 static int protected_restore_fp_context(void __user *sc)
 162 {
 163         struct mips_abi *abi = current->thread.abi;
 164         uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
 165         uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
 166         int err, tmp __maybe_unused;
 167
 168         /*
 169          * EVA does not have userland equivalents of ldc1 or sdc1, so we
 170          * disable the FPU here such that the code below simply copies to
 171          * the kernel FP context.
 172          */
 173         if (config_enabled(CONFIG_EVA))
 174                 lose_fpu(0);
 175
 176         while (1) {
 177                 lock_fpu_owner();
 178                 if (is_fpu_owner()) {
 179                         err = restore_fp_context(sc);
 180                         unlock_fpu_owner();
 181                 } else {
 182                         unlock_fpu_owner();
 183                         err = copy_fp_from_sigcontext(sc);
 184                 }
 185                 if (likely(!err))
 186                         break;
 187                 /* touch the sigcontext and try again */
 188                 err = __get_user(tmp, &fpregs[0]) |
 189                         __get_user(tmp, &fpregs[31]) |
 190                         __get_user(tmp, csr);
 191                 if (err)
 192                         break;  /* really bad sigcontext */
 193         }
 194
 195         return err;
 196 }
 197
 198 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 199 {
 200         int err = 0;
 201         int i;
 202         unsigned int used_math;
 203
 204         err |= __put_user(regs->cp0_epc, &sc->sc_pc);
 205
 206         err |= __put_user(0, &sc->sc_regs[0]);
 207         for (i = 1; i < 32; i++)
 208                 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
 209
 210 #ifdef CONFIG_CPU_HAS_SMARTMIPS
 211         err |= __put_user(regs->acx, &sc->sc_acx);
 212 #endif
 213         err |= __put_user(regs->hi, &sc->sc_mdhi);
 214         err |= __put_user(regs->lo, &sc->sc_mdlo);
 215         if (cpu_has_dsp) {
 216                 err |= __put_user(mfhi1(), &sc->sc_hi1);
 217                 err |= __put_user(mflo1(), &sc->sc_lo1);
 218                 err |= __put_user(mfhi2(), &sc->sc_hi2);
 219                 err |= __put_user(mflo2(), &sc->sc_lo2);
 220                 err |= __put_user(mfhi3(), &sc->sc_hi3);
 221                 err |= __put_user(mflo3(), &sc->sc_lo3);
 222                 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
 223         }
 224
 225         used_math = !!used_math();
 226         err |= __put_user(used_math, &sc->sc_used_math);
 227
 228         if (used_math) {
 229                 /*
 230                  * Save FPU state to signal context. Signal handler
 231                  * will "inherit" current FPU state.
 232                  */
 233                 err |= protected_save_fp_context(sc);
 234         }
 235         return err;
 236 }
 237
 238 int fpcsr_pending(unsigned int __user *fpcsr)
 239 {
 240         int err, sig = 0;
 241         unsigned int csr, enabled;
 242
 243         err = __get_user(csr, fpcsr);
 244         enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
 245         /*
 246          * If the signal handler set some FPU exceptions, clear it and
 247          * send SIGFPE.
 248          */
 249         if (csr & enabled) {
 250                 csr &= ~enabled;
 251                 err |= __put_user(csr, fpcsr);
 252                 sig = SIGFPE;
 253         }
 254         return err ?: sig;
 255 }
 256
 257 static int
 258 check_and_restore_fp_context(void __user *sc)
 259 {
 260         struct mips_abi *abi = current->thread.abi;
 261         int err, sig;
 262
 263         err = sig = fpcsr_pending(sc + abi->off_sc_fpc_csr);
 264         if (err > 0)
 265                 err = 0;
 266         err |= protected_restore_fp_context(sc);
 267         return err ?: sig;
 268 }
 269
 270 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 271 {
 272         unsigned int used_math;
 273         unsigned long treg;
 274         int err = 0;
 275         int i;
 276
 277         /* Always make any pending restarted system calls return -EINTR */
 278         current->restart_block.fn = do_no_restart_syscall;
 279
 280         err |= __get_user(regs->cp0_epc, &sc->sc_pc);
 281
 282 #ifdef CONFIG_CPU_HAS_SMARTMIPS
 283         err |= __get_user(regs->acx, &sc->sc_acx);
 284 #endif
 285         err |= __get_user(regs->hi, &sc->sc_mdhi);
 286         err |= __get_user(regs->lo, &sc->sc_mdlo);
 287         if (cpu_has_dsp) {
 288                 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
 289                 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
 290                 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
 291                 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
 292                 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
 293                 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
 294                 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
 295         }
 296
 297         for (i = 1; i < 32; i++)
 298                 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
 299
 300         err |= __get_user(used_math, &sc->sc_used_math);
 301         conditional_used_math(used_math);
 302
 303         if (used_math) {
 304                 /* restore fpu context if we have used it before */
 305                 if (!err)
 306                         err = check_and_restore_fp_context(sc);
 307         } else {
 308                 /* signal handler may have used FPU.  Give it up. */
 309                 lose_fpu(0);
 310         }
 311
 312         return err;
 313 }
 314
 315 void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 316                           size_t frame_size)
 317 {
 318         unsigned long sp;
 319
 320         /* Default to using normal stack */
 321         sp = regs->regs[29];
 322
 323         /*
 324          * FPU emulator may have it's own trampoline active just
 325          * above the user stack, 16-bytes before the next lowest
 326          * 16 byte boundary.  Try to avoid trashing it.
 327          */
 328         sp -= 32;
 329
 330         sp = sigsp(sp, ksig);
 331
 332         return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
 333 }
 334
 335 /*
 336  * Atomically swap in the new signal mask, and wait for a signal.
 337  */
 338
 339 #ifdef CONFIG_TRAD_SIGNALS
 340 SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
 341 {
 342         return sys_rt_sigsuspend(uset, sizeof(sigset_t));
 343 }
 344 #endif
 345
 346 #ifdef CONFIG_TRAD_SIGNALS
 347 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
 348         struct sigaction __user *, oact)
 349 {
 350         struct k_sigaction new_ka, old_ka;
 351         int ret;
 352         int err = 0;
 353
 354         if (act) {
 355                 old_sigset_t mask;
 356
 357                 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
 358                         return -EFAULT;
 359                 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
 360                 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 361                 err |= __get_user(mask, &act->sa_mask.sig[0]);
 362                 if (err)
 363                         return -EFAULT;
 364
 365                 siginitset(&new_ka.sa.sa_mask, mask);
 366         }
 367
 368         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 369
 370         if (!ret && oact) {
 371                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
 372                         return -EFAULT;
 373                 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 374                 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
 375                 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
 376                 err |= __put_user(0, &oact->sa_mask.sig[1]);
 377                 err |= __put_user(0, &oact->sa_mask.sig[2]);
 378                 err |= __put_user(0, &oact->sa_mask.sig[3]);
 379                 if (err)
 380                         return -EFAULT;
 381         }
 382
 383         return ret;
 384 }
 385 #endif
 386
 387 #ifdef CONFIG_TRAD_SIGNALS
 388 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 389 {
 390         struct sigframe __user *frame;
 391         sigset_t blocked;
 392         int sig;
 393
 394         frame = (struct sigframe __user *) regs.regs[29];
 395         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 396                 goto badframe;
 397         if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
 398                 goto badframe;
 399
 400         set_current_blocked(&blocked);
 401
 402         sig = restore_sigcontext(&regs, &frame->sf_sc);
 403         if (sig < 0)
 404                 goto badframe;
 405         else if (sig)
 406                 force_sig(sig, current);
 407
 408         /*
 409          * Don't let your children do this ...
 410          */
 411         __asm__ __volatile__(
 412                 "move\t$29, %0\n\t"
 413                 "j\tsyscall_exit"
 414                 :/* no outputs */
 415                 :"r" (&regs));
 416         /* Unreached */
 417
 418 badframe:
 419         force_sig(SIGSEGV, current);
 420 }
 421 #endif /* CONFIG_TRAD_SIGNALS */
 422
 423 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 424 {
 425         struct rt_sigframe __user *frame;
 426         sigset_t set;
 427         int sig;
 428
 429         frame = (struct rt_sigframe __user *) regs.regs[29];
 430         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 431                 goto badframe;
 432         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 433                 goto badframe;
 434
 435         set_current_blocked(&set);
 436
 437         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 438         if (sig < 0)
 439                 goto badframe;
 440         else if (sig)
 441                 force_sig(sig, current);
 442
 443         if (restore_altstack(&frame->rs_uc.uc_stack))
 444                 goto badframe;
 445
 446         /*
 447          * Don't let your children do this ...
 448          */
 449         __asm__ __volatile__(
 450                 "move\t$29, %0\n\t"
 451                 "j\tsyscall_exit"
 452                 :/* no outputs */
 453                 :"r" (&regs));
 454         /* Unreached */
 455
 456 badframe:
 457         force_sig(SIGSEGV, current);
 458 }
 459
 460 #ifdef CONFIG_TRAD_SIGNALS
 461 static int setup_frame(void *sig_return, struct ksignal *ksig,
 462                        struct pt_regs *regs, sigset_t *set)
 463 {
 464         struct sigframe __user *frame;
 465         int err = 0;
 466
 467         frame = get_sigframe(ksig, regs, sizeof(*frame));
 468         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 469                 return -EFAULT;
 470
 471         err |= setup_sigcontext(regs, &frame->sf_sc);
 472         err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
 473         if (err)
 474                 return -EFAULT;
 475
 476         /*
 477          * Arguments to signal handler:
 478          *
 479          *   a0 = signal number
 480          *   a1 = 0 (should be cause)
 481          *   a2 = pointer to struct sigcontext
 482          *
 483          * $25 and c0_epc point to the signal handler, $29 points to the
 484          * struct sigframe.
 485          */
 486         regs->regs[ 4] = ksig->sig;
 487         regs->regs[ 5] = 0;
 488         regs->regs[ 6] = (unsigned long) &frame->sf_sc;
 489         regs->regs[29] = (unsigned long) frame;
 490         regs->regs[31] = (unsigned long) sig_return;
 491         regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
 492
 493         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 494                current->comm, current->pid,
 495                frame, regs->cp0_epc, regs->regs[31]);
 496         return 0;
 497 }
 498 #endif
 499
 500 static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
 501                           struct pt_regs *regs, sigset_t *set)
 502 {
 503         struct rt_sigframe __user *frame;
 504         int err = 0;
 505
 506         frame = get_sigframe(ksig, regs, sizeof(*frame));
 507         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 508                 return -EFAULT;
 509
 510         /* Create siginfo.  */
 511         err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
 512
 513         /* Create the ucontext.  */
 514         err |= __put_user(0, &frame->rs_uc.uc_flags);
 515         err |= __put_user(NULL, &frame->rs_uc.uc_link);
 516         err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
 517         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 518         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 519
 520         if (err)
 521                 return -EFAULT;
 522
 523         /*
 524          * Arguments to signal handler:
 525          *
 526          *   a0 = signal number
 527          *   a1 = 0 (should be cause)
 528          *   a2 = pointer to ucontext
 529          *
 530          * $25 and c0_epc point to the signal handler, $29 points to
 531          * the struct rt_sigframe.
 532          */
 533         regs->regs[ 4] = ksig->sig;
 534         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 535         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 536         regs->regs[29] = (unsigned long) frame;
 537         regs->regs[31] = (unsigned long) sig_return;
 538         regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
 539
 540         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 541                current->comm, current->pid,
 542                frame, regs->cp0_epc, regs->regs[31]);
 543
 544         return 0;
 545 }
 546
 547 struct mips_abi mips_abi = {
 548 #ifdef CONFIG_TRAD_SIGNALS
 549         .setup_frame    = setup_frame,
 550         .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline),
 551 #endif
 552         .setup_rt_frame = setup_rt_frame,
 553         .rt_signal_return_offset =
 554                 offsetof(struct mips_vdso, rt_signal_trampoline),
 555         .restart        = __NR_restart_syscall,
 556
 557         .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
 558         .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
 559         .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
 560 };
 561
 562 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 563 {
 564         sigset_t *oldset = sigmask_to_save();
 565         int ret;
 566         struct mips_abi *abi = current->thread.abi;
 567 #ifdef CONFIG_CPU_MICROMIPS
 568         void *vdso;
 569         unsigned long tmp = (unsigned long)current->mm->context.vdso;
 570
 571         set_isa16_mode(tmp);
 572         vdso = (void *)tmp;
 573 #else
 574         void *vdso = current->mm->context.vdso;
 575 #endif
 576
 577         if (regs->regs[0]) {
 578                 switch(regs->regs[2]) {
 579                 case ERESTART_RESTARTBLOCK:
 580                 case ERESTARTNOHAND:
 581                         regs->regs[2] = EINTR;
 582                         break;
 583                 case ERESTARTSYS:
 584                         if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
 585                                 regs->regs[2] = EINTR;
 586                                 break;
 587                         }
 588                 /* fallthrough */
 589                 case ERESTARTNOINTR:
 590                         regs->regs[7] = regs->regs[26];
 591                         regs->regs[2] = regs->regs[0];
 592                         regs->cp0_epc -= 4;
 593                 }
 594
 595                 regs->regs[0] = 0;              /* Don't deal with this again.  */
 596         }
 597
 598         if (sig_uses_siginfo(&ksig->ka))
 599                 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
 600                                           ksig, regs, oldset);
 601         else
 602                 ret = abi->setup_frame(vdso + abi->signal_return_offset, ksig,
 603                                        regs, oldset);
 604
 605         signal_setup_done(ret, ksig, 0);
 606 }
 607
 608 static void do_signal(struct pt_regs *regs)
 609 {
 610         struct ksignal ksig;
 611
 612         if (get_signal(&ksig)) {
 613                 /* Whee!  Actually deliver the signal.  */
 614                 handle_signal(&ksig, regs);
 615                 return;
 616         }
 617
 618         if (regs->regs[0]) {
 619                 switch (regs->regs[2]) {
 620                 case ERESTARTNOHAND:
 621                 case ERESTARTSYS:
 622                 case ERESTARTNOINTR:
 623                         regs->regs[2] = regs->regs[0];
 624                         regs->regs[7] = regs->regs[26];
 625                         regs->cp0_epc -= 4;
 626                         break;
 627
 628                 case ERESTART_RESTARTBLOCK:
 629                         regs->regs[2] = current->thread.abi->restart;
 630                         regs->regs[7] = regs->regs[26];
 631                         regs->cp0_epc -= 4;
 632                         break;
 633                 }
 634                 regs->regs[0] = 0;      /* Don't deal with this again.  */
 635         }
 636
 637         /*
 638          * If there's no signal to deliver, we just put the saved sigmask
 639          * back
 640          */
 641         restore_saved_sigmask();
 642 }
 643
 644 /*
 645  * notification of userspace execution resumption
 646  * - triggered by the TIF_WORK_MASK flags
 647  */
 648 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 649         __u32 thread_info_flags)
 650 {
 651         local_irq_enable();
 652
 653         user_exit();
 654
 655         /* deal with pending signal delivery */
 656         if (thread_info_flags & _TIF_SIGPENDING)
 657                 do_signal(regs);
 658
 659         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 660                 clear_thread_flag(TIF_NOTIFY_RESUME);
 661                 tracehook_notify_resume(regs);
 662         }
 663
 664         user_enter();
 665 }
 666
 667 #ifdef CONFIG_SMP
 668 static int smp_save_fp_context(void __user *sc)
 669 {
 670         return raw_cpu_has_fpu
 671                ? save_hw_fp_context(sc)
 672                : copy_fp_to_sigcontext(sc);
 673 }
 674
 675 static int smp_restore_fp_context(void __user *sc)
 676 {
 677         return raw_cpu_has_fpu
 678                ? restore_hw_fp_context(sc)
 679                : copy_fp_from_sigcontext(sc);
 680 }
 681 #endif
 682
 683 static int signal_setup(void)
 684 {
 685 #ifdef CONFIG_SMP
 686         /* For now just do the cpu_has_fpu check when the functions are invoked */
 687         save_fp_context = smp_save_fp_context;
 688         restore_fp_context = smp_restore_fp_context;
 689 #else
 690         if (cpu_has_fpu) {
 691                 save_fp_context = save_hw_fp_context;
 692                 restore_fp_context = restore_hw_fp_context;
 693         } else {
 694                 save_fp_context = copy_fp_to_sigcontext;
 695                 restore_fp_context = copy_fp_from_sigcontext;
 696         }
 697 #endif /* CONFIG_SMP */
 698
 699         return 0;
 700 }
 701
 702 arch_initcall(signal_setup);