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