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