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 return sigsuspend(&newset); 259 } 260 #endif 261 262 asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs) 263 { 264 sigset_t newset; 265 sigset_t __user *unewset; 266 size_t sigsetsize; 267 268 /* XXX Don't preclude handling different sized sigset_t's. */ 269 sigsetsize = regs.regs[5]; 270 if (sigsetsize != sizeof(sigset_t)) 271 return -EINVAL; 272 273 unewset = (sigset_t __user *) regs.regs[4]; 274 if (copy_from_user(&newset, unewset, sizeof(newset))) 275 return -EFAULT; 276 return sigsuspend(&newset); 277 } 278 279 #ifdef CONFIG_TRAD_SIGNALS 280 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act, 281 struct sigaction __user *, oact) 282 { 283 struct k_sigaction new_ka, old_ka; 284 int ret; 285 int err = 0; 286 287 if (act) { 288 old_sigset_t mask; 289 290 if (!access_ok(VERIFY_READ, act, sizeof(*act))) 291 return -EFAULT; 292 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler); 293 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags); 294 err |= __get_user(mask, &act->sa_mask.sig[0]); 295 if (err) 296 return -EFAULT; 297 298 siginitset(&new_ka.sa.sa_mask, mask); 299 } 300 301 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 302 303 if (!ret && oact) { 304 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact))) 305 return -EFAULT; 306 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags); 307 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler); 308 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig); 309 err |= __put_user(0, &oact->sa_mask.sig[1]); 310 err |= __put_user(0, &oact->sa_mask.sig[2]); 311 err |= __put_user(0, &oact->sa_mask.sig[3]); 312 if (err) 313 return -EFAULT; 314 } 315 316 return ret; 317 } 318 #endif 319 320 asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs) 321 { 322 const stack_t __user *uss = (const stack_t __user *) regs.regs[4]; 323 stack_t __user *uoss = (stack_t __user *) regs.regs[5]; 324 unsigned long usp = regs.regs[29]; 325 326 return do_sigaltstack(uss, uoss, usp); 327 } 328 329 #ifdef CONFIG_TRAD_SIGNALS 330 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs) 331 { 332 struct sigframe __user *frame; 333 sigset_t blocked; 334 int sig; 335 336 frame = (struct sigframe __user *) regs.regs[29]; 337 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 338 goto badframe; 339 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked))) 340 goto badframe; 341 342 sigdelsetmask(&blocked, ~_BLOCKABLE); 343 set_current_blocked(&blocked); 344 345 sig = restore_sigcontext(®s, &frame->sf_sc); 346 if (sig < 0) 347 goto badframe; 348 else if (sig) 349 force_sig(sig, current); 350 351 /* 352 * Don't let your children do this ... 353 */ 354 __asm__ __volatile__( 355 "move\t$29, %0\n\t" 356 "j\tsyscall_exit" 357 :/* no outputs */ 358 :"r" (®s)); 359 /* Unreached */ 360 361 badframe: 362 force_sig(SIGSEGV, current); 363 } 364 #endif /* CONFIG_TRAD_SIGNALS */ 365 366 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) 367 { 368 struct rt_sigframe __user *frame; 369 sigset_t set; 370 int sig; 371 372 frame = (struct rt_sigframe __user *) regs.regs[29]; 373 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 374 goto badframe; 375 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set))) 376 goto badframe; 377 378 sigdelsetmask(&set, ~_BLOCKABLE); 379 set_current_blocked(&set); 380 381 sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext); 382 if (sig < 0) 383 goto badframe; 384 else if (sig) 385 force_sig(sig, current); 386 387 /* It is more difficult to avoid calling this function than to 388 call it and ignore errors. */ 389 do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]); 390 391 /* 392 * Don't let your children do this ... 393 */ 394 __asm__ __volatile__( 395 "move\t$29, %0\n\t" 396 "j\tsyscall_exit" 397 :/* no outputs */ 398 :"r" (®s)); 399 /* Unreached */ 400 401 badframe: 402 force_sig(SIGSEGV, current); 403 } 404 405 #ifdef CONFIG_TRAD_SIGNALS 406 static int setup_frame(void *sig_return, struct k_sigaction *ka, 407 struct pt_regs *regs, int signr, sigset_t *set) 408 { 409 struct sigframe __user *frame; 410 int err = 0; 411 412 frame = get_sigframe(ka, regs, sizeof(*frame)); 413 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) 414 goto give_sigsegv; 415 416 err |= setup_sigcontext(regs, &frame->sf_sc); 417 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set)); 418 if (err) 419 goto give_sigsegv; 420 421 /* 422 * Arguments to signal handler: 423 * 424 * a0 = signal number 425 * a1 = 0 (should be cause) 426 * a2 = pointer to struct sigcontext 427 * 428 * $25 and c0_epc point to the signal handler, $29 points to the 429 * struct sigframe. 430 */ 431 regs->regs[ 4] = signr; 432 regs->regs[ 5] = 0; 433 regs->regs[ 6] = (unsigned long) &frame->sf_sc; 434 regs->regs[29] = (unsigned long) frame; 435 regs->regs[31] = (unsigned long) sig_return; 436 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; 437 438 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 439 current->comm, current->pid, 440 frame, regs->cp0_epc, regs->regs[31]); 441 return 0; 442 443 give_sigsegv: 444 force_sigsegv(signr, current); 445 return -EFAULT; 446 } 447 #endif 448 449 static int setup_rt_frame(void *sig_return, struct k_sigaction *ka, 450 struct pt_regs *regs, int signr, sigset_t *set, 451 siginfo_t *info) 452 { 453 struct rt_sigframe __user *frame; 454 int err = 0; 455 456 frame = get_sigframe(ka, regs, sizeof(*frame)); 457 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) 458 goto give_sigsegv; 459 460 /* Create siginfo. */ 461 err |= copy_siginfo_to_user(&frame->rs_info, info); 462 463 /* Create the ucontext. */ 464 err |= __put_user(0, &frame->rs_uc.uc_flags); 465 err |= __put_user(NULL, &frame->rs_uc.uc_link); 466 err |= __put_user((void __user *)current->sas_ss_sp, 467 &frame->rs_uc.uc_stack.ss_sp); 468 err |= __put_user(sas_ss_flags(regs->regs[29]), 469 &frame->rs_uc.uc_stack.ss_flags); 470 err |= __put_user(current->sas_ss_size, 471 &frame->rs_uc.uc_stack.ss_size); 472 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); 473 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set)); 474 475 if (err) 476 goto give_sigsegv; 477 478 /* 479 * Arguments to signal handler: 480 * 481 * a0 = signal number 482 * a1 = 0 (should be cause) 483 * a2 = pointer to ucontext 484 * 485 * $25 and c0_epc point to the signal handler, $29 points to 486 * the struct rt_sigframe. 487 */ 488 regs->regs[ 4] = signr; 489 regs->regs[ 5] = (unsigned long) &frame->rs_info; 490 regs->regs[ 6] = (unsigned long) &frame->rs_uc; 491 regs->regs[29] = (unsigned long) frame; 492 regs->regs[31] = (unsigned long) sig_return; 493 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler; 494 495 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", 496 current->comm, current->pid, 497 frame, regs->cp0_epc, regs->regs[31]); 498 499 return 0; 500 501 give_sigsegv: 502 force_sigsegv(signr, current); 503 return -EFAULT; 504 } 505 506 struct mips_abi mips_abi = { 507 #ifdef CONFIG_TRAD_SIGNALS 508 .setup_frame = setup_frame, 509 .signal_return_offset = offsetof(struct mips_vdso, signal_trampoline), 510 #endif 511 .setup_rt_frame = setup_rt_frame, 512 .rt_signal_return_offset = 513 offsetof(struct mips_vdso, rt_signal_trampoline), 514 .restart = __NR_restart_syscall 515 }; 516 517 static int handle_signal(unsigned long sig, siginfo_t *info, 518 struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs) 519 { 520 int ret; 521 struct mips_abi *abi = current->thread.abi; 522 void *vdso = current->mm->context.vdso; 523 524 if (regs->regs[0]) { 525 switch(regs->regs[2]) { 526 case ERESTART_RESTARTBLOCK: 527 case ERESTARTNOHAND: 528 regs->regs[2] = EINTR; 529 break; 530 case ERESTARTSYS: 531 if (!(ka->sa.sa_flags & SA_RESTART)) { 532 regs->regs[2] = EINTR; 533 break; 534 } 535 /* fallthrough */ 536 case ERESTARTNOINTR: 537 regs->regs[7] = regs->regs[26]; 538 regs->regs[2] = regs->regs[0]; 539 regs->cp0_epc -= 4; 540 } 541 542 regs->regs[0] = 0; /* Don't deal with this again. */ 543 } 544 545 if (sig_uses_siginfo(ka)) 546 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, 547 ka, regs, sig, oldset, info); 548 else 549 ret = abi->setup_frame(vdso + abi->signal_return_offset, 550 ka, regs, sig, oldset); 551 552 if (ret) 553 return ret; 554 555 block_sigmask(ka, sig); 556 557 return ret; 558 } 559 560 static void do_signal(struct pt_regs *regs) 561 { 562 struct k_sigaction ka; 563 sigset_t *oldset; 564 siginfo_t info; 565 int signr; 566 567 /* 568 * We want the common case to go fast, which is why we may in certain 569 * cases get here from kernel mode. Just return without doing anything 570 * if so. 571 */ 572 if (!user_mode(regs)) 573 return; 574 575 if (test_thread_flag(TIF_RESTORE_SIGMASK)) 576 oldset = ¤t->saved_sigmask; 577 else 578 oldset = ¤t->blocked; 579 580 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 581 if (signr > 0) { 582 /* Whee! Actually deliver the signal. */ 583 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { 584 /* 585 * A signal was successfully delivered; the saved 586 * sigmask will have been stored in the signal frame, 587 * and will be restored by sigreturn, so we can simply 588 * clear the TIF_RESTORE_SIGMASK flag. 589 */ 590 if (test_thread_flag(TIF_RESTORE_SIGMASK)) 591 clear_thread_flag(TIF_RESTORE_SIGMASK); 592 } 593 594 return; 595 } 596 597 if (regs->regs[0]) { 598 if (regs->regs[2] == ERESTARTNOHAND || 599 regs->regs[2] == ERESTARTSYS || 600 regs->regs[2] == ERESTARTNOINTR) { 601 regs->regs[2] = regs->regs[0]; 602 regs->regs[7] = regs->regs[26]; 603 regs->cp0_epc -= 4; 604 } 605 if (regs->regs[2] == ERESTART_RESTARTBLOCK) { 606 regs->regs[2] = current->thread.abi->restart; 607 regs->regs[7] = regs->regs[26]; 608 regs->cp0_epc -= 4; 609 } 610 regs->regs[0] = 0; /* Don't deal with this again. */ 611 } 612 613 /* 614 * If there's no signal to deliver, we just put the saved sigmask 615 * back 616 */ 617 if (test_thread_flag(TIF_RESTORE_SIGMASK)) { 618 clear_thread_flag(TIF_RESTORE_SIGMASK); 619 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); 620 } 621 } 622 623 /* 624 * notification of userspace execution resumption 625 * - triggered by the TIF_WORK_MASK flags 626 */ 627 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, 628 __u32 thread_info_flags) 629 { 630 local_irq_enable(); 631 632 /* deal with pending signal delivery */ 633 if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) 634 do_signal(regs); 635 636 if (thread_info_flags & _TIF_NOTIFY_RESUME) { 637 clear_thread_flag(TIF_NOTIFY_RESUME); 638 tracehook_notify_resume(regs); 639 if (current->replacement_session_keyring) 640 key_replace_session_keyring(); 641 } 642 } 643 644 #ifdef CONFIG_SMP 645 static int smp_save_fp_context(struct sigcontext __user *sc) 646 { 647 return raw_cpu_has_fpu 648 ? _save_fp_context(sc) 649 : fpu_emulator_save_context(sc); 650 } 651 652 static int smp_restore_fp_context(struct sigcontext __user *sc) 653 { 654 return raw_cpu_has_fpu 655 ? _restore_fp_context(sc) 656 : fpu_emulator_restore_context(sc); 657 } 658 #endif 659 660 static int signal_setup(void) 661 { 662 #ifdef CONFIG_SMP 663 /* For now just do the cpu_has_fpu check when the functions are invoked */ 664 save_fp_context = smp_save_fp_context; 665 restore_fp_context = smp_restore_fp_context; 666 #else 667 if (cpu_has_fpu) { 668 save_fp_context = _save_fp_context; 669 restore_fp_context = _restore_fp_context; 670 } else { 671 save_fp_context = fpu_emulator_save_context; 672 restore_fp_context = fpu_emulator_restore_context; 673 } 674 #endif 675 676 return 0; 677 } 678 679 arch_initcall(signal_setup); 680