arch/sparc/kernel/signal_32.c

   1 /*  linux/arch/sparc/kernel/signal.c
   2  *
   3  *  Copyright (C) 1991, 1992  Linus Torvalds
   4  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
   6  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
   7  */
   8
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/signal.h>
  12 #include <linux/errno.h>
  13 #include <linux/wait.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/unistd.h>
  16 #include <linux/mm.h>
  17 #include <linux/tty.h>
  18 #include <linux/smp.h>
  19 #include <linux/binfmts.h>      /* do_coredum */
  20 #include <linux/bitops.h>
  21 #include <linux/tracehook.h>
  22
  23 #include <asm/uaccess.h>
  24 #include <asm/ptrace.h>
  25 #include <asm/pgalloc.h>
  26 #include <asm/pgtable.h>
  27 #include <asm/cacheflush.h>     /* flush_sig_insns */
  28
  29 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  30
  31 extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
  32                    void *fpqueue, unsigned long *fpqdepth);
  33 extern void fpload(unsigned long *fpregs, unsigned long *fsr);
  34
  35 struct signal_frame {
  36         struct sparc_stackf     ss;
  37         __siginfo32_t           info;
  38         __siginfo_fpu_t __user  *fpu_save;
  39         unsigned long           insns[2] __attribute__ ((aligned (8)));
  40         unsigned int            extramask[_NSIG_WORDS - 1];
  41         unsigned int            extra_size; /* Should be 0 */
  42         __siginfo_fpu_t         fpu_state;
  43 };
  44
  45 struct rt_signal_frame {
  46         struct sparc_stackf     ss;
  47         siginfo_t               info;
  48         struct pt_regs          regs;
  49         sigset_t                mask;
  50         __siginfo_fpu_t __user  *fpu_save;
  51         unsigned int            insns[2];
  52         stack_t                 stack;
  53         unsigned int            extra_size; /* Should be 0 */
  54         __siginfo_fpu_t         fpu_state;
  55 };
  56
  57 /* Align macros */
  58 #define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
  59 #define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
  60
  61 static int _sigpause_common(old_sigset_t set)
  62 {
  63         set &= _BLOCKABLE;
  64         spin_lock_irq(&current->sighand->siglock);
  65         current->saved_sigmask = current->blocked;
  66         siginitset(&current->blocked, set);
  67         recalc_sigpending();
  68         spin_unlock_irq(&current->sighand->siglock);
  69
  70         current->state = TASK_INTERRUPTIBLE;
  71         schedule();
  72         set_thread_flag(TIF_RESTORE_SIGMASK);
  73
  74         return -ERESTARTNOHAND;
  75 }
  76
  77 asmlinkage int sys_sigsuspend(old_sigset_t set)
  78 {
  79         return _sigpause_common(set);
  80 }
  81
  82 static inline int
  83 restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
  84 {
  85         int err;
  86 #ifdef CONFIG_SMP
  87         if (test_tsk_thread_flag(current, TIF_USEDFPU))
  88                 regs->psr &= ~PSR_EF;
  89 #else
  90         if (current == last_task_used_math) {
  91                 last_task_used_math = NULL;
  92                 regs->psr &= ~PSR_EF;
  93         }
  94 #endif
  95         set_used_math();
  96         clear_tsk_thread_flag(current, TIF_USEDFPU);
  97
  98         if (!access_ok(VERIFY_READ, fpu, sizeof(*fpu)))
  99                 return -EFAULT;
 100
 101         err = __copy_from_user(&current->thread.float_regs[0], &fpu->si_float_regs[0],
 102                                (sizeof(unsigned long) * 32));
 103         err |= __get_user(current->thread.fsr, &fpu->si_fsr);
 104         err |= __get_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
 105         if (current->thread.fpqdepth != 0)
 106                 err |= __copy_from_user(&current->thread.fpqueue[0],
 107                                         &fpu->si_fpqueue[0],
 108                                         ((sizeof(unsigned long) +
 109                                         (sizeof(unsigned long *)))*16));
 110         return err;
 111 }
 112
 113 asmlinkage void do_sigreturn(struct pt_regs *regs)
 114 {
 115         struct signal_frame __user *sf;
 116         unsigned long up_psr, pc, npc;
 117         sigset_t set;
 118         __siginfo_fpu_t __user *fpu_save;
 119         int err;
 120
 121         /* Always make any pending restarted system calls return -EINTR */
 122         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 123
 124         synchronize_user_stack();
 125
 126         sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
 127
 128         /* 1. Make sure we are not getting garbage from the user */
 129         if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
 130                 goto segv_and_exit;
 131
 132         if (((unsigned long) sf) & 3)
 133                 goto segv_and_exit;
 134
 135         err = __get_user(pc,  &sf->info.si_regs.pc);
 136         err |= __get_user(npc, &sf->info.si_regs.npc);
 137
 138         if ((pc | npc) & 3)
 139                 goto segv_and_exit;
 140
 141         /* 2. Restore the state */
 142         up_psr = regs->psr;
 143         err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
 144
 145         /* User can only change condition codes and FPU enabling in %psr. */
 146         regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
 147                   | (regs->psr & (PSR_ICC | PSR_EF));
 148
 149         /* Prevent syscall restart.  */
 150         pt_regs_clear_syscall(regs);
 151
 152         err |= __get_user(fpu_save, &sf->fpu_save);
 153
 154         if (fpu_save)
 155                 err |= restore_fpu_state(regs, fpu_save);
 156
 157         /* This is pretty much atomic, no amount locking would prevent
 158          * the races which exist anyways.
 159          */
 160         err |= __get_user(set.sig[0], &sf->info.si_mask);
 161         err |= __copy_from_user(&set.sig[1], &sf->extramask,
 162                                 (_NSIG_WORDS-1) * sizeof(unsigned int));
 163
 164         if (err)
 165                 goto segv_and_exit;
 166
 167         sigdelsetmask(&set, ~_BLOCKABLE);
 168         spin_lock_irq(&current->sighand->siglock);
 169         current->blocked = set;
 170         recalc_sigpending();
 171         spin_unlock_irq(&current->sighand->siglock);
 172         return;
 173
 174 segv_and_exit:
 175         force_sig(SIGSEGV, current);
 176 }
 177
 178 asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
 179 {
 180         struct rt_signal_frame __user *sf;
 181         unsigned int psr, pc, npc;
 182         __siginfo_fpu_t __user *fpu_save;
 183         mm_segment_t old_fs;
 184         sigset_t set;
 185         stack_t st;
 186         int err;
 187
 188         synchronize_user_stack();
 189         sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
 190         if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
 191             (((unsigned long) sf) & 0x03))
 192                 goto segv;
 193
 194         err = __get_user(pc, &sf->regs.pc);
 195         err |= __get_user(npc, &sf->regs.npc);
 196         err |= ((pc | npc) & 0x03);
 197
 198         err |= __get_user(regs->y, &sf->regs.y);
 199         err |= __get_user(psr, &sf->regs.psr);
 200
 201         err |= __copy_from_user(&regs->u_regs[UREG_G1],
 202                                 &sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
 203
 204         regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
 205
 206         /* Prevent syscall restart.  */
 207         pt_regs_clear_syscall(regs);
 208
 209         err |= __get_user(fpu_save, &sf->fpu_save);
 210
 211         if (fpu_save)
 212                 err |= restore_fpu_state(regs, fpu_save);
 213         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
 214
 215         err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
 216
 217         if (err)
 218                 goto segv;
 219
 220         regs->pc = pc;
 221         regs->npc = npc;
 222
 223         /* It is more difficult to avoid calling this function than to
 224          * call it and ignore errors.
 225          */
 226         old_fs = get_fs();
 227         set_fs(KERNEL_DS);
 228         do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
 229         set_fs(old_fs);
 230
 231         sigdelsetmask(&set, ~_BLOCKABLE);
 232         spin_lock_irq(&current->sighand->siglock);
 233         current->blocked = set;
 234         recalc_sigpending();
 235         spin_unlock_irq(&current->sighand->siglock);
 236         return;
 237 segv:
 238         force_sig(SIGSEGV, current);
 239 }
 240
 241 /* Checks if the fp is valid */
 242 static inline int invalid_frame_pointer(void __user *fp, int fplen)
 243 {
 244         if ((((unsigned long) fp) & 7) ||
 245             !__access_ok((unsigned long)fp, fplen) ||
 246             ((sparc_cpu_model == sun4 || sparc_cpu_model == sun4c) &&
 247              ((unsigned long) fp < 0xe0000000 && (unsigned long) fp >= 0x20000000)))
 248                 return 1;
 249
 250         return 0;
 251 }
 252
 253 static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
 254 {
 255         unsigned long sp = regs->u_regs[UREG_FP];
 256
 257         /*
 258          * If we are on the alternate signal stack and would overflow it, don't.
 259          * Return an always-bogus address instead so we will die with SIGSEGV.
 260          */
 261         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 262                 return (void __user *) -1L;
 263
 264         /* This is the X/Open sanctioned signal stack switching.  */
 265         if (sa->sa_flags & SA_ONSTACK) {
 266                 if (sas_ss_flags(sp) == 0)
 267                         sp = current->sas_ss_sp + current->sas_ss_size;
 268         }
 269
 270         sp -= framesize;
 271
 272         /* Always align the stack frame.  This handles two cases.  First,
 273          * sigaltstack need not be mindful of platform specific stack
 274          * alignment.  Second, if we took this signal because the stack
 275          * is not aligned properly, we'd like to take the signal cleanly
 276          * and report that.
 277          */
 278         sp &= ~15UL;
 279
 280         return (void __user *) sp;
 281 }
 282
 283 static inline int
 284 save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
 285 {
 286         int err = 0;
 287 #ifdef CONFIG_SMP
 288         if (test_tsk_thread_flag(current, TIF_USEDFPU)) {
 289                 put_psr(get_psr() | PSR_EF);
 290                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 291                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 292                 regs->psr &= ~(PSR_EF);
 293                 clear_tsk_thread_flag(current, TIF_USEDFPU);
 294         }
 295 #else
 296         if (current == last_task_used_math) {
 297                 put_psr(get_psr() | PSR_EF);
 298                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 299                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 300                 last_task_used_math = NULL;
 301                 regs->psr &= ~(PSR_EF);
 302         }
 303 #endif
 304         err |= __copy_to_user(&fpu->si_float_regs[0],
 305                               &current->thread.float_regs[0],
 306                               (sizeof(unsigned long) * 32));
 307         err |= __put_user(current->thread.fsr, &fpu->si_fsr);
 308         err |= __put_user(current->thread.fpqdepth, &fpu->si_fpqdepth);
 309         if (current->thread.fpqdepth != 0)
 310                 err |= __copy_to_user(&fpu->si_fpqueue[0],
 311                                       &current->thread.fpqueue[0],
 312                                       ((sizeof(unsigned long) +
 313                                       (sizeof(unsigned long *)))*16));
 314         clear_used_math();
 315         return err;
 316 }
 317
 318 static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
 319                        int signo, sigset_t *oldset)
 320 {
 321         struct signal_frame __user *sf;
 322         int sigframe_size, err;
 323
 324         /* 1. Make sure everything is clean */
 325         synchronize_user_stack();
 326
 327         sigframe_size = SF_ALIGNEDSZ;
 328         if (!used_math())
 329                 sigframe_size -= sizeof(__siginfo_fpu_t);
 330
 331         sf = (struct signal_frame __user *)
 332                 get_sigframe(&ka->sa, regs, sigframe_size);
 333
 334         if (invalid_frame_pointer(sf, sigframe_size))
 335                 goto sigill_and_return;
 336
 337         if (current_thread_info()->w_saved != 0)
 338                 goto sigill_and_return;
 339
 340         /* 2. Save the current process state */
 341         err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
 342
 343         err |= __put_user(0, &sf->extra_size);
 344
 345         if (used_math()) {
 346                 err |= save_fpu_state(regs, &sf->fpu_state);
 347                 err |= __put_user(&sf->fpu_state, &sf->fpu_save);
 348         } else {
 349                 err |= __put_user(0, &sf->fpu_save);
 350         }
 351
 352         err |= __put_user(oldset->sig[0], &sf->info.si_mask);
 353         err |= __copy_to_user(sf->extramask, &oldset->sig[1],
 354                               (_NSIG_WORDS - 1) * sizeof(unsigned int));
 355         err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 356                               sizeof(struct reg_window32));
 357         if (err)
 358                 goto sigsegv;
 359
 360         /* 3. signal handler back-trampoline and parameters */
 361         regs->u_regs[UREG_FP] = (unsigned long) sf;
 362         regs->u_regs[UREG_I0] = signo;
 363         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 364         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
 365
 366         /* 4. signal handler */
 367         regs->pc = (unsigned long) ka->sa.sa_handler;
 368         regs->npc = (regs->pc + 4);
 369
 370         /* 5. return to kernel instructions */
 371         if (ka->ka_restorer)
 372                 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 373         else {
 374                 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 375
 376                 /* mov __NR_sigreturn, %g1 */
 377                 err |= __put_user(0x821020d8, &sf->insns[0]);
 378
 379                 /* t 0x10 */
 380                 err |= __put_user(0x91d02010, &sf->insns[1]);
 381                 if (err)
 382                         goto sigsegv;
 383
 384                 /* Flush instruction space. */
 385                 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 386         }
 387         return 0;
 388
 389 sigill_and_return:
 390         do_exit(SIGILL);
 391         return -EINVAL;
 392
 393 sigsegv:
 394         force_sigsegv(signo, current);
 395         return -EFAULT;
 396 }
 397
 398 static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
 399                           int signo, sigset_t *oldset, siginfo_t *info)
 400 {
 401         struct rt_signal_frame __user *sf;
 402         int sigframe_size;
 403         unsigned int psr;
 404         int err;
 405
 406         synchronize_user_stack();
 407         sigframe_size = RT_ALIGNEDSZ;
 408         if (!used_math())
 409                 sigframe_size -= sizeof(__siginfo_fpu_t);
 410         sf = (struct rt_signal_frame __user *)
 411                 get_sigframe(&ka->sa, regs, sigframe_size);
 412         if (invalid_frame_pointer(sf, sigframe_size))
 413                 goto sigill;
 414         if (current_thread_info()->w_saved != 0)
 415                 goto sigill;
 416
 417         err  = __put_user(regs->pc, &sf->regs.pc);
 418         err |= __put_user(regs->npc, &sf->regs.npc);
 419         err |= __put_user(regs->y, &sf->regs.y);
 420         psr = regs->psr;
 421         if (used_math())
 422                 psr |= PSR_EF;
 423         err |= __put_user(psr, &sf->regs.psr);
 424         err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
 425         err |= __put_user(0, &sf->extra_size);
 426
 427         if (psr & PSR_EF) {
 428                 err |= save_fpu_state(regs, &sf->fpu_state);
 429                 err |= __put_user(&sf->fpu_state, &sf->fpu_save);
 430         } else {
 431                 err |= __put_user(0, &sf->fpu_save);
 432         }
 433         err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
 434
 435         /* Setup sigaltstack */
 436         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
 437         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
 438         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
 439
 440         err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
 441                               sizeof(struct reg_window32));
 442
 443         err |= copy_siginfo_to_user(&sf->info, info);
 444
 445         if (err)
 446                 goto sigsegv;
 447
 448         regs->u_regs[UREG_FP] = (unsigned long) sf;
 449         regs->u_regs[UREG_I0] = signo;
 450         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
 451         regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
 452
 453         regs->pc = (unsigned long) ka->sa.sa_handler;
 454         regs->npc = (regs->pc + 4);
 455
 456         if (ka->ka_restorer)
 457                 regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
 458         else {
 459                 regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
 460
 461                 /* mov __NR_sigreturn, %g1 */
 462                 err |= __put_user(0x821020d8, &sf->insns[0]);
 463
 464                 /* t 0x10 */
 465                 err |= __put_user(0x91d02010, &sf->insns[1]);
 466                 if (err)
 467                         goto sigsegv;
 468
 469                 /* Flush instruction space. */
 470                 flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
 471         }
 472         return 0;
 473
 474 sigill:
 475         do_exit(SIGILL);
 476         return -EINVAL;
 477
 478 sigsegv:
 479         force_sigsegv(signo, current);
 480         return -EFAULT;
 481 }
 482
 483 static inline int
 484 handle_signal(unsigned long signr, struct k_sigaction *ka,
 485               siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
 486 {
 487         int err;
 488
 489         if (ka->sa.sa_flags & SA_SIGINFO)
 490                 err = setup_rt_frame(ka, regs, signr, oldset, info);
 491         else
 492                 err = setup_frame(ka, regs, signr, oldset);
 493
 494         if (err)
 495                 return err;
 496
 497         spin_lock_irq(&current->sighand->siglock);
 498         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 499         if (!(ka->sa.sa_flags & SA_NOMASK))
 500                 sigaddset(&current->blocked, signr);
 501         recalc_sigpending();
 502         spin_unlock_irq(&current->sighand->siglock);
 503
 504         tracehook_signal_handler(signr, info, ka, regs, 0);
 505
 506         return 0;
 507 }
 508
 509 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
 510                                    struct sigaction *sa)
 511 {
 512         switch(regs->u_regs[UREG_I0]) {
 513         case ERESTART_RESTARTBLOCK:
 514         case ERESTARTNOHAND:
 515         no_system_call_restart:
 516                 regs->u_regs[UREG_I0] = EINTR;
 517                 regs->psr |= PSR_C;
 518                 break;
 519         case ERESTARTSYS:
 520                 if (!(sa->sa_flags & SA_RESTART))
 521                         goto no_system_call_restart;
 522                 /* fallthrough */
 523         case ERESTARTNOINTR:
 524                 regs->u_regs[UREG_I0] = orig_i0;
 525                 regs->pc -= 4;
 526                 regs->npc -= 4;
 527         }
 528 }
 529
 530 /* Note that 'init' is a special process: it doesn't get signals it doesn't
 531  * want to handle. Thus you cannot kill init even with a SIGKILL even by
 532  * mistake.
 533  */
 534 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 535 {
 536         struct k_sigaction ka;
 537         int restart_syscall;
 538         sigset_t *oldset;
 539         siginfo_t info;
 540         int signr;
 541
 542         if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
 543                 restart_syscall = 1;
 544         else
 545                 restart_syscall = 0;
 546
 547         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 548                 oldset = &current->saved_sigmask;
 549         else
 550                 oldset = &current->blocked;
 551
 552         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 553
 554         /* If the debugger messes with the program counter, it clears
 555          * the software "in syscall" bit, directing us to not perform
 556          * a syscall restart.
 557          */
 558         if (restart_syscall && !pt_regs_is_syscall(regs))
 559                 restart_syscall = 0;
 560
 561         if (signr > 0) {
 562                 if (restart_syscall)
 563                         syscall_restart(orig_i0, regs, &ka.sa);
 564                 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
 565                         /* a signal was successfully delivered; the saved
 566                          * sigmask will have been stored in the signal frame,
 567                          * and will be restored by sigreturn, so we can simply
 568                          * clear the TIF_RESTORE_SIGMASK flag.
 569                          */
 570                         if (test_thread_flag(TIF_RESTORE_SIGMASK))
 571                                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 572                 }
 573                 return;
 574         }
 575         if (restart_syscall &&
 576             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
 577              regs->u_regs[UREG_I0] == ERESTARTSYS ||
 578              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
 579                 /* replay the system call when we are done */
 580                 regs->u_regs[UREG_I0] = orig_i0;
 581                 regs->pc -= 4;
 582                 regs->npc -= 4;
 583                 pt_regs_clear_syscall(regs);
 584         }
 585         if (restart_syscall &&
 586             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
 587                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
 588                 regs->pc -= 4;
 589                 regs->npc -= 4;
 590                 pt_regs_clear_syscall(regs);
 591         }
 592
 593         /* if there's no signal to deliver, we just put the saved sigmask
 594          * back
 595          */
 596         if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 597                 clear_thread_flag(TIF_RESTORE_SIGMASK);
 598                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 599         }
 600 }
 601
 602 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
 603                       unsigned long thread_info_flags)
 604 {
 605         if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
 606                 do_signal(regs, orig_i0);
 607         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 608                 clear_thread_flag(TIF_NOTIFY_RESUME);
 609                 tracehook_notify_resume(regs);
 610                 if (current->replacement_session_keyring)
 611                         key_replace_session_keyring();
 612         }
 613 }
 614
 615 asmlinkage int
 616 do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
 617                 unsigned long sp)
 618 {
 619         int ret = -EFAULT;
 620
 621         /* First see if old state is wanted. */
 622         if (ossptr) {
 623                 if (put_user(current->sas_ss_sp + current->sas_ss_size,
 624                              &ossptr->the_stack) ||
 625                     __put_user(on_sig_stack(sp), &ossptr->cur_status))
 626                         goto out;
 627         }
 628
 629         /* Now see if we want to update the new state. */
 630         if (ssptr) {
 631                 char *ss_sp;
 632
 633                 if (get_user(ss_sp, &ssptr->the_stack))
 634                         goto out;
 635                 /* If the current stack was set with sigaltstack, don't
 636                    swap stacks while we are on it.  */
 637                 ret = -EPERM;
 638                 if (current->sas_ss_sp && on_sig_stack(sp))
 639                         goto out;
 640
 641                 /* Since we don't know the extent of the stack, and we don't
 642                    track onstack-ness, but rather calculate it, we must
 643                    presume a size.  Ho hum this interface is lossy.  */
 644                 current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
 645                 current->sas_ss_size = SIGSTKSZ;
 646         }
 647         ret = 0;
 648 out:
 649         return ret;
 650 }