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