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/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/personality.h>
  14 #include <linux/smp.h>
  15 #include <linux/kernel.h>
  16 #include <linux/signal.h>
  17 #include <linux/errno.h>
  18 #include <linux/wait.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/unistd.h>
  21 #include <linux/compiler.h>
  22 #include <linux/syscalls.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/tracehook.h>
  25
  26 #include <asm/abi.h>
  27 #include <asm/asm.h>
  28 #include <linux/bitops.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/fpu.h>
  31 #include <asm/sim.h>
  32 #include <asm/ucontext.h>
  33 #include <asm/cpu-features.h>
  34 #include <asm/war.h>
  35
  36 #include "signal-common.h"
  37
  38 static int (*save_fp_context)(struct sigcontext __user *sc);
  39 static int (*restore_fp_context)(struct sigcontext __user *sc);
  40
  41 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
  42 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
  43
  44 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
  45 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
  46
  47 /*
  48  * Horribly complicated - with the bloody RM9000 workarounds enabled
  49  * the signal trampolines is moving to the end of the structure so we can
  50  * increase the alignment without breaking software compatibility.
  51  */
  52 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
  53
  54 struct sigframe {
  55         u32 sf_ass[4];          /* argument save space for o32 */
  56         u32 sf_code[2];         /* signal trampoline */
  57         struct sigcontext sf_sc;
  58         sigset_t sf_mask;
  59 };
  60
  61 struct rt_sigframe {
  62         u32 rs_ass[4];          /* argument save space for o32 */
  63         u32 rs_code[2];         /* signal trampoline */
  64         struct siginfo rs_info;
  65         struct ucontext rs_uc;
  66 };
  67
  68 #else
  69
  70 struct sigframe {
  71         u32 sf_ass[4];                  /* argument save space for o32 */
  72         u32 sf_pad[2];
  73         struct sigcontext sf_sc;        /* hw context */
  74         sigset_t sf_mask;
  75         u32 sf_code[8] ____cacheline_aligned;   /* signal trampoline */
  76 };
  77
  78 struct rt_sigframe {
  79         u32 rs_ass[4];                  /* argument save space for o32 */
  80         u32 rs_pad[2];
  81         struct siginfo rs_info;
  82         struct ucontext rs_uc;
  83         u32 rs_code[8] ____cacheline_aligned;   /* signal trampoline */
  84 };
  85
  86 #endif
  87
  88 /*
  89  * Helper routines
  90  */
  91 static int protected_save_fp_context(struct sigcontext __user *sc)
  92 {
  93         int err;
  94         while (1) {
  95                 lock_fpu_owner();
  96                 own_fpu_inatomic(1);
  97                 err = save_fp_context(sc); /* this might fail */
  98                 unlock_fpu_owner();
  99                 if (likely(!err))
 100                         break;
 101                 /* touch the sigcontext and try again */
 102                 err = __put_user(0, &sc->sc_fpregs[0]) |
 103                         __put_user(0, &sc->sc_fpregs[31]) |
 104                         __put_user(0, &sc->sc_fpc_csr);
 105                 if (err)
 106                         break;  /* really bad sigcontext */
 107         }
 108         return err;
 109 }
 110
 111 static int protected_restore_fp_context(struct sigcontext __user *sc)
 112 {
 113         int err, tmp;
 114         while (1) {
 115                 lock_fpu_owner();
 116                 own_fpu_inatomic(0);
 117                 err = restore_fp_context(sc); /* this might fail */
 118                 unlock_fpu_owner();
 119                 if (likely(!err))
 120                         break;
 121                 /* touch the sigcontext and try again */
 122                 err = __get_user(tmp, &sc->sc_fpregs[0]) |
 123                         __get_user(tmp, &sc->sc_fpregs[31]) |
 124                         __get_user(tmp, &sc->sc_fpc_csr);
 125                 if (err)
 126                         break;  /* really bad sigcontext */
 127         }
 128         return err;
 129 }
 130
 131 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 132 {
 133         int err = 0;
 134         int i;
 135         unsigned int used_math;
 136
 137         err |= __put_user(regs->cp0_epc, &sc->sc_pc);
 138
 139         err |= __put_user(0, &sc->sc_regs[0]);
 140         for (i = 1; i < 32; i++)
 141                 err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
 142
 143 #ifdef CONFIG_CPU_HAS_SMARTMIPS
 144         err |= __put_user(regs->acx, &sc->sc_acx);
 145 #endif
 146         err |= __put_user(regs->hi, &sc->sc_mdhi);
 147         err |= __put_user(regs->lo, &sc->sc_mdlo);
 148         if (cpu_has_dsp) {
 149                 err |= __put_user(mfhi1(), &sc->sc_hi1);
 150                 err |= __put_user(mflo1(), &sc->sc_lo1);
 151                 err |= __put_user(mfhi2(), &sc->sc_hi2);
 152                 err |= __put_user(mflo2(), &sc->sc_lo2);
 153                 err |= __put_user(mfhi3(), &sc->sc_hi3);
 154                 err |= __put_user(mflo3(), &sc->sc_lo3);
 155                 err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
 156         }
 157
 158         used_math = !!used_math();
 159         err |= __put_user(used_math, &sc->sc_used_math);
 160
 161         if (used_math) {
 162                 /*
 163                  * Save FPU state to signal context. Signal handler
 164                  * will "inherit" current FPU state.
 165                  */
 166                 err |= protected_save_fp_context(sc);
 167         }
 168         return err;
 169 }
 170
 171 int fpcsr_pending(unsigned int __user *fpcsr)
 172 {
 173         int err, sig = 0;
 174         unsigned int csr, enabled;
 175
 176         err = __get_user(csr, fpcsr);
 177         enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
 178         /*
 179          * If the signal handler set some FPU exceptions, clear it and
 180          * send SIGFPE.
 181          */
 182         if (csr & enabled) {
 183                 csr &= ~enabled;
 184                 err |= __put_user(csr, fpcsr);
 185                 sig = SIGFPE;
 186         }
 187         return err ?: sig;
 188 }
 189
 190 static int
 191 check_and_restore_fp_context(struct sigcontext __user *sc)
 192 {
 193         int err, sig;
 194
 195         err = sig = fpcsr_pending(&sc->sc_fpc_csr);
 196         if (err > 0)
 197                 err = 0;
 198         err |= protected_restore_fp_context(sc);
 199         return err ?: sig;
 200 }
 201
 202 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 203 {
 204         unsigned int used_math;
 205         unsigned long treg;
 206         int err = 0;
 207         int i;
 208
 209         /* Always make any pending restarted system calls return -EINTR */
 210         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 211
 212         err |= __get_user(regs->cp0_epc, &sc->sc_pc);
 213
 214 #ifdef CONFIG_CPU_HAS_SMARTMIPS
 215         err |= __get_user(regs->acx, &sc->sc_acx);
 216 #endif
 217         err |= __get_user(regs->hi, &sc->sc_mdhi);
 218         err |= __get_user(regs->lo, &sc->sc_mdlo);
 219         if (cpu_has_dsp) {
 220                 err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
 221                 err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
 222                 err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
 223                 err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
 224                 err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
 225                 err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
 226                 err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
 227         }
 228
 229         for (i = 1; i < 32; i++)
 230                 err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
 231
 232         err |= __get_user(used_math, &sc->sc_used_math);
 233         conditional_used_math(used_math);
 234
 235         if (used_math) {
 236                 /* restore fpu context if we have used it before */
 237                 if (!err)
 238                         err = check_and_restore_fp_context(sc);
 239         } else {
 240                 /* signal handler may have used FPU.  Give it up. */
 241                 lose_fpu(0);
 242         }
 243
 244         return err;
 245 }
 246
 247 void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
 248                           size_t frame_size)
 249 {
 250         unsigned long sp;
 251
 252         /* Default to using normal stack */
 253         sp = regs->regs[29];
 254
 255         /*
 256          * FPU emulator may have it's own trampoline active just
 257          * above the user stack, 16-bytes before the next lowest
 258          * 16 byte boundary.  Try to avoid trashing it.
 259          */
 260         sp -= 32;
 261
 262         /* This is the X/Open sanctioned signal stack switching.  */
 263         if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
 264                 sp = current->sas_ss_sp + current->sas_ss_size;
 265
 266         return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
 267 }
 268
 269 int install_sigtramp(unsigned int __user *tramp, unsigned int syscall)
 270 {
 271         int err;
 272
 273         /*
 274          * Set up the return code ...
 275          *
 276          *         li      v0, __NR__foo_sigreturn
 277          *         syscall
 278          */
 279
 280         err = __put_user(0x24020000 + syscall, tramp + 0);
 281         err |= __put_user(0x0000000c         , tramp + 1);
 282         if (ICACHE_REFILLS_WORKAROUND_WAR) {
 283                 err |= __put_user(0, tramp + 2);
 284                 err |= __put_user(0, tramp + 3);
 285                 err |= __put_user(0, tramp + 4);
 286                 err |= __put_user(0, tramp + 5);
 287                 err |= __put_user(0, tramp + 6);
 288                 err |= __put_user(0, tramp + 7);
 289         }
 290         flush_cache_sigtramp((unsigned long) tramp);
 291
 292         return err;
 293 }
 294
 295 /*
 296  * Atomically swap in the new signal mask, and wait for a signal.
 297  */
 298
 299 #ifdef CONFIG_TRAD_SIGNALS
 300 asmlinkage int sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
 301 {
 302         sigset_t newset;
 303         sigset_t __user *uset;
 304
 305         uset = (sigset_t __user *) regs.regs[4];
 306         if (copy_from_user(&newset, uset, sizeof(sigset_t)))
 307                 return -EFAULT;
 308         sigdelsetmask(&newset, ~_BLOCKABLE);
 309
 310         spin_lock_irq(&current->sighand->siglock);
 311         current->saved_sigmask = current->blocked;
 312         current->blocked = newset;
 313         recalc_sigpending();
 314         spin_unlock_irq(&current->sighand->siglock);
 315
 316         current->state = TASK_INTERRUPTIBLE;
 317         schedule();
 318         set_thread_flag(TIF_RESTORE_SIGMASK);
 319         return -ERESTARTNOHAND;
 320 }
 321 #endif
 322
 323 asmlinkage int sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
 324 {
 325         sigset_t newset;
 326         sigset_t __user *unewset;
 327         size_t sigsetsize;
 328
 329         /* XXX Don't preclude handling different sized sigset_t's.  */
 330         sigsetsize = regs.regs[5];
 331         if (sigsetsize != sizeof(sigset_t))
 332                 return -EINVAL;
 333
 334         unewset = (sigset_t __user *) regs.regs[4];
 335         if (copy_from_user(&newset, unewset, sizeof(newset)))
 336                 return -EFAULT;
 337         sigdelsetmask(&newset, ~_BLOCKABLE);
 338
 339         spin_lock_irq(&current->sighand->siglock);
 340         current->saved_sigmask = current->blocked;
 341         current->blocked = newset;
 342         recalc_sigpending();
 343         spin_unlock_irq(&current->sighand->siglock);
 344
 345         current->state = TASK_INTERRUPTIBLE;
 346         schedule();
 347         set_thread_flag(TIF_RESTORE_SIGMASK);
 348         return -ERESTARTNOHAND;
 349 }
 350
 351 #ifdef CONFIG_TRAD_SIGNALS
 352 SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
 353         struct sigaction __user *, oact)
 354 {
 355         struct k_sigaction new_ka, old_ka;
 356         int ret;
 357         int err = 0;
 358
 359         if (act) {
 360                 old_sigset_t mask;
 361
 362                 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
 363                         return -EFAULT;
 364                 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
 365                 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 366                 err |= __get_user(mask, &act->sa_mask.sig[0]);
 367                 if (err)
 368                         return -EFAULT;
 369
 370                 siginitset(&new_ka.sa.sa_mask, mask);
 371         }
 372
 373         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 374
 375         if (!ret && oact) {
 376                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
 377                         return -EFAULT;
 378                 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 379                 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
 380                 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
 381                 err |= __put_user(0, &oact->sa_mask.sig[1]);
 382                 err |= __put_user(0, &oact->sa_mask.sig[2]);
 383                 err |= __put_user(0, &oact->sa_mask.sig[3]);
 384                 if (err)
 385                         return -EFAULT;
 386         }
 387
 388         return ret;
 389 }
 390 #endif
 391
 392 asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
 393 {
 394         const stack_t __user *uss = (const stack_t __user *) regs.regs[4];
 395         stack_t __user *uoss = (stack_t __user *) regs.regs[5];
 396         unsigned long usp = regs.regs[29];
 397
 398         return do_sigaltstack(uss, uoss, usp);
 399 }
 400
 401 #ifdef CONFIG_TRAD_SIGNALS
 402 asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 403 {
 404         struct sigframe __user *frame;
 405         sigset_t blocked;
 406         int sig;
 407
 408         frame = (struct sigframe __user *) regs.regs[29];
 409         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 410                 goto badframe;
 411         if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
 412                 goto badframe;
 413
 414         sigdelsetmask(&blocked, ~_BLOCKABLE);
 415         spin_lock_irq(&current->sighand->siglock);
 416         current->blocked = blocked;
 417         recalc_sigpending();
 418         spin_unlock_irq(&current->sighand->siglock);
 419
 420         sig = restore_sigcontext(&regs, &frame->sf_sc);
 421         if (sig < 0)
 422                 goto badframe;
 423         else if (sig)
 424                 force_sig(sig, current);
 425
 426         /*
 427          * Don't let your children do this ...
 428          */
 429         __asm__ __volatile__(
 430                 "move\t$29, %0\n\t"
 431                 "j\tsyscall_exit"
 432                 :/* no outputs */
 433                 :"r" (&regs));
 434         /* Unreached */
 435
 436 badframe:
 437         force_sig(SIGSEGV, current);
 438 }
 439 #endif /* CONFIG_TRAD_SIGNALS */
 440
 441 asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 442 {
 443         struct rt_sigframe __user *frame;
 444         sigset_t set;
 445         stack_t st;
 446         int sig;
 447
 448         frame = (struct rt_sigframe __user *) regs.regs[29];
 449         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 450                 goto badframe;
 451         if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
 452                 goto badframe;
 453
 454         sigdelsetmask(&set, ~_BLOCKABLE);
 455         spin_lock_irq(&current->sighand->siglock);
 456         current->blocked = set;
 457         recalc_sigpending();
 458         spin_unlock_irq(&current->sighand->siglock);
 459
 460         sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
 461         if (sig < 0)
 462                 goto badframe;
 463         else if (sig)
 464                 force_sig(sig, current);
 465
 466         if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
 467                 goto badframe;
 468         /* It is more difficult to avoid calling this function than to
 469            call it and ignore errors.  */
 470         do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
 471
 472         /*
 473          * Don't let your children do this ...
 474          */
 475         __asm__ __volatile__(
 476                 "move\t$29, %0\n\t"
 477                 "j\tsyscall_exit"
 478                 :/* no outputs */
 479                 :"r" (&regs));
 480         /* Unreached */
 481
 482 badframe:
 483         force_sig(SIGSEGV, current);
 484 }
 485
 486 #ifdef CONFIG_TRAD_SIGNALS
 487 static int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
 488         int signr, sigset_t *set)
 489 {
 490         struct sigframe __user *frame;
 491         int err = 0;
 492
 493         frame = get_sigframe(ka, regs, sizeof(*frame));
 494         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 495                 goto give_sigsegv;
 496
 497         err |= install_sigtramp(frame->sf_code, __NR_sigreturn);
 498
 499         err |= setup_sigcontext(regs, &frame->sf_sc);
 500         err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
 501         if (err)
 502                 goto give_sigsegv;
 503
 504         /*
 505          * Arguments to signal handler:
 506          *
 507          *   a0 = signal number
 508          *   a1 = 0 (should be cause)
 509          *   a2 = pointer to struct sigcontext
 510          *
 511          * $25 and c0_epc point to the signal handler, $29 points to the
 512          * struct sigframe.
 513          */
 514         regs->regs[ 4] = signr;
 515         regs->regs[ 5] = 0;
 516         regs->regs[ 6] = (unsigned long) &frame->sf_sc;
 517         regs->regs[29] = (unsigned long) frame;
 518         regs->regs[31] = (unsigned long) frame->sf_code;
 519         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 520
 521         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 522                current->comm, current->pid,
 523                frame, regs->cp0_epc, regs->regs[31]);
 524         return 0;
 525
 526 give_sigsegv:
 527         force_sigsegv(signr, current);
 528         return -EFAULT;
 529 }
 530 #endif
 531
 532 static int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
 533         int signr, sigset_t *set, siginfo_t *info)
 534 {
 535         struct rt_sigframe __user *frame;
 536         int err = 0;
 537
 538         frame = get_sigframe(ka, regs, sizeof(*frame));
 539         if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
 540                 goto give_sigsegv;
 541
 542         err |= install_sigtramp(frame->rs_code, __NR_rt_sigreturn);
 543
 544         /* Create siginfo.  */
 545         err |= copy_siginfo_to_user(&frame->rs_info, info);
 546
 547         /* Create the ucontext.  */
 548         err |= __put_user(0, &frame->rs_uc.uc_flags);
 549         err |= __put_user(NULL, &frame->rs_uc.uc_link);
 550         err |= __put_user((void __user *)current->sas_ss_sp,
 551                           &frame->rs_uc.uc_stack.ss_sp);
 552         err |= __put_user(sas_ss_flags(regs->regs[29]),
 553                           &frame->rs_uc.uc_stack.ss_flags);
 554         err |= __put_user(current->sas_ss_size,
 555                           &frame->rs_uc.uc_stack.ss_size);
 556         err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 557         err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
 558
 559         if (err)
 560                 goto give_sigsegv;
 561
 562         /*
 563          * Arguments to signal handler:
 564          *
 565          *   a0 = signal number
 566          *   a1 = 0 (should be cause)
 567          *   a2 = pointer to ucontext
 568          *
 569          * $25 and c0_epc point to the signal handler, $29 points to
 570          * the struct rt_sigframe.
 571          */
 572         regs->regs[ 4] = signr;
 573         regs->regs[ 5] = (unsigned long) &frame->rs_info;
 574         regs->regs[ 6] = (unsigned long) &frame->rs_uc;
 575         regs->regs[29] = (unsigned long) frame;
 576         regs->regs[31] = (unsigned long) frame->rs_code;
 577         regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
 578
 579         DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
 580                current->comm, current->pid,
 581                frame, regs->cp0_epc, regs->regs[31]);
 582
 583         return 0;
 584
 585 give_sigsegv:
 586         force_sigsegv(signr, current);
 587         return -EFAULT;
 588 }
 589
 590 struct mips_abi mips_abi = {
 591 #ifdef CONFIG_TRAD_SIGNALS
 592         .setup_frame    = setup_frame,
 593 #endif
 594         .setup_rt_frame = setup_rt_frame,
 595         .restart        = __NR_restart_syscall
 596 };
 597
 598 static int handle_signal(unsigned long sig, siginfo_t *info,
 599         struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
 600 {
 601         int ret;
 602
 603         switch(regs->regs[0]) {
 604         case ERESTART_RESTARTBLOCK:
 605         case ERESTARTNOHAND:
 606                 regs->regs[2] = EINTR;
 607                 break;
 608         case ERESTARTSYS:
 609                 if (!(ka->sa.sa_flags & SA_RESTART)) {
 610                         regs->regs[2] = EINTR;
 611                         break;
 612                 }
 613         /* fallthrough */
 614         case ERESTARTNOINTR:            /* Userland will reload $v0.  */
 615                 regs->regs[7] = regs->regs[26];
 616                 regs->cp0_epc -= 8;
 617         }
 618
 619         regs->regs[0] = 0;              /* Don't deal with this again.  */
 620
 621         if (sig_uses_siginfo(ka))
 622                 ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info);
 623         else
 624                 ret = current->thread.abi->setup_frame(ka, regs, sig, oldset);
 625
 626         spin_lock_irq(&current->sighand->siglock);
 627         sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
 628         if (!(ka->sa.sa_flags & SA_NODEFER))
 629                 sigaddset(&current->blocked, sig);
 630         recalc_sigpending();
 631         spin_unlock_irq(&current->sighand->siglock);
 632
 633         return ret;
 634 }
 635
 636 static void do_signal(struct pt_regs *regs)
 637 {
 638         struct k_sigaction ka;
 639         sigset_t *oldset;
 640         siginfo_t info;
 641         int signr;
 642
 643         /*
 644          * We want the common case to go fast, which is why we may in certain
 645          * cases get here from kernel mode. Just return without doing anything
 646          * if so.
 647          */
 648         if (!user_mode(regs))
 649                 return;
 650
 651         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 652                 oldset = &current->saved_sigmask;
 653         else
 654                 oldset = &current->blocked;
 655
 656         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 657         if (signr > 0) {
 658                 /* Whee!  Actually deliver the signal.  */
 659                 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
 660                         /*
 661                          * A signal was successfully delivered; the saved
 662                          * sigmask will have been stored in the signal frame,
 663                          * and will be restored by sigreturn, so we can simply
 664                          * clear the TIF_RESTORE_SIGMASK flag.
 665                          */
 666                         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 667                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 668                 }
 669
 670                 return;
 671         }
 672
 673         /*
 674          * Who's code doesn't conform to the restartable syscall convention
 675          * dies here!!!  The li instruction, a single machine instruction,
 676          * must directly be followed by the syscall instruction.
 677          */
 678         if (regs->regs[0]) {
 679                 if (regs->regs[2] == ERESTARTNOHAND ||
 680                     regs->regs[2] == ERESTARTSYS ||
 681                     regs->regs[2] == ERESTARTNOINTR) {
 682                         regs->regs[7] = regs->regs[26];
 683                         regs->cp0_epc -= 8;
 684                 }
 685                 if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
 686                         regs->regs[2] = current->thread.abi->restart;
 687                         regs->regs[7] = regs->regs[26];
 688                         regs->cp0_epc -= 4;
 689                 }
 690                 regs->regs[0] = 0;      /* Don't deal with this again.  */
 691         }
 692
 693         /*
 694          * If there's no signal to deliver, we just put the saved sigmask
 695          * back
 696          */
 697         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 698                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 699                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 700         }
 701 }
 702
 703 /*
 704  * notification of userspace execution resumption
 705  * - triggered by the TIF_WORK_MASK flags
 706  */
 707 asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
 708         __u32 thread_info_flags)
 709 {
 710         /* deal with pending signal delivery */
 711         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 712                 do_signal(regs);
 713
 714         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 715                 clear_thread_flag(TIF_NOTIFY_RESUME);
 716                 tracehook_notify_resume(regs);
 717                 if (current->replacement_session_keyring)
 718                         key_replace_session_keyring();
 719         }
 720 }
 721
 722 #ifdef CONFIG_SMP
 723 static int smp_save_fp_context(struct sigcontext __user *sc)
 724 {
 725         return raw_cpu_has_fpu
 726                ? _save_fp_context(sc)
 727                : fpu_emulator_save_context(sc);
 728 }
 729
 730 static int smp_restore_fp_context(struct sigcontext __user *sc)
 731 {
 732         return raw_cpu_has_fpu
 733                ? _restore_fp_context(sc)
 734                : fpu_emulator_restore_context(sc);
 735 }
 736 #endif
 737
 738 static int signal_setup(void)
 739 {
 740 #ifdef CONFIG_SMP
 741         /* For now just do the cpu_has_fpu check when the functions are invoked */
 742         save_fp_context = smp_save_fp_context;
 743         restore_fp_context = smp_restore_fp_context;
 744 #else
 745         if (cpu_has_fpu) {
 746                 save_fp_context = _save_fp_context;
 747                 restore_fp_context = _restore_fp_context;
 748         } else {
 749                 save_fp_context = fpu_emulator_save_context;
 750                 restore_fp_context = fpu_emulator_restore_context;
 751         }
 752 #endif
 753
 754         return 0;
 755 }
 756
 757 arch_initcall(signal_setup);