arch/s390/kernel/compat_signal.c

   1 /*
   2  *  arch/s390/kernel/compat_signal.c
   3  *
   4  *    Copyright (C) IBM Corp. 2000,2006
   5  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
   6  *               Gerhard Tonn (ton@de.ibm.com)
   7  *
   8  *  Copyright (C) 1991, 1992  Linus Torvalds
   9  *
  10  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/compat.h>
  15 #include <linux/sched.h>
  16 #include <linux/mm.h>
  17 #include <linux/smp.h>
  18 #include <linux/smp_lock.h>
  19 #include <linux/kernel.h>
  20 #include <linux/signal.h>
  21 #include <linux/errno.h>
  22 #include <linux/wait.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/unistd.h>
  25 #include <linux/stddef.h>
  26 #include <linux/tty.h>
  27 #include <linux/personality.h>
  28 #include <linux/binfmts.h>
  29 #include <asm/ucontext.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/lowcore.h>
  32 #include "compat_linux.h"
  33 #include "compat_ptrace.h"
  34
  35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
  36
  37 typedef struct
  38 {
  39         __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
  40         struct sigcontext32 sc;
  41         _sigregs32 sregs;
  42         int signo;
  43         __u8 retcode[S390_SYSCALL_SIZE];
  44 } sigframe32;
  45
  46 typedef struct
  47 {
  48         __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
  49         __u8 retcode[S390_SYSCALL_SIZE];
  50         compat_siginfo_t info;
  51         struct ucontext32 uc;
  52 } rt_sigframe32;
  53
  54 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
  55 {
  56         int err;
  57
  58         if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
  59                 return -EFAULT;
  60
  61         /* If you change siginfo_t structure, please be sure
  62            this code is fixed accordingly.
  63            It should never copy any pad contained in the structure
  64            to avoid security leaks, but must copy the generic
  65            3 ints plus the relevant union member.
  66            This routine must convert siginfo from 64bit to 32bit as well
  67            at the same time.  */
  68         err = __put_user(from->si_signo, &to->si_signo);
  69         err |= __put_user(from->si_errno, &to->si_errno);
  70         err |= __put_user((short)from->si_code, &to->si_code);
  71         if (from->si_code < 0)
  72                 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
  73         else {
  74                 switch (from->si_code >> 16) {
  75                 case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
  76                 case __SI_MESGQ >> 16:
  77                         err |= __put_user(from->si_int, &to->si_int);
  78                         /* fallthrough */
  79                 case __SI_KILL >> 16:
  80                         err |= __put_user(from->si_pid, &to->si_pid);
  81                         err |= __put_user(from->si_uid, &to->si_uid);
  82                         break;
  83                 case __SI_CHLD >> 16:
  84                         err |= __put_user(from->si_pid, &to->si_pid);
  85                         err |= __put_user(from->si_uid, &to->si_uid);
  86                         err |= __put_user(from->si_utime, &to->si_utime);
  87                         err |= __put_user(from->si_stime, &to->si_stime);
  88                         err |= __put_user(from->si_status, &to->si_status);
  89                         break;
  90                 case __SI_FAULT >> 16:
  91                         err |= __put_user((unsigned long) from->si_addr,
  92                                           &to->si_addr);
  93                         break;
  94                 case __SI_POLL >> 16:
  95                         err |= __put_user(from->si_band, &to->si_band);
  96                         err |= __put_user(from->si_fd, &to->si_fd);
  97                         break;
  98                 case __SI_TIMER >> 16:
  99                         err |= __put_user(from->si_tid, &to->si_tid);
 100                         err |= __put_user(from->si_overrun, &to->si_overrun);
 101                         err |= __put_user(from->si_int, &to->si_int);
 102                         break;
 103                 default:
 104                         break;
 105                 }
 106         }
 107         return err;
 108 }
 109
 110 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 111 {
 112         int err;
 113         u32 tmp;
 114
 115         if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
 116                 return -EFAULT;
 117
 118         err = __get_user(to->si_signo, &from->si_signo);
 119         err |= __get_user(to->si_errno, &from->si_errno);
 120         err |= __get_user(to->si_code, &from->si_code);
 121
 122         if (to->si_code < 0)
 123                 err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
 124         else {
 125                 switch (to->si_code >> 16) {
 126                 case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
 127                 case __SI_MESGQ >> 16:
 128                         err |= __get_user(to->si_int, &from->si_int);
 129                         /* fallthrough */
 130                 case __SI_KILL >> 16:
 131                         err |= __get_user(to->si_pid, &from->si_pid);
 132                         err |= __get_user(to->si_uid, &from->si_uid);
 133                         break;
 134                 case __SI_CHLD >> 16:
 135                         err |= __get_user(to->si_pid, &from->si_pid);
 136                         err |= __get_user(to->si_uid, &from->si_uid);
 137                         err |= __get_user(to->si_utime, &from->si_utime);
 138                         err |= __get_user(to->si_stime, &from->si_stime);
 139                         err |= __get_user(to->si_status, &from->si_status);
 140                         break;
 141                 case __SI_FAULT >> 16:
 142                         err |= __get_user(tmp, &from->si_addr);
 143                         to->si_addr = (void __user *)(u64) (tmp & PSW32_ADDR_INSN);
 144                         break;
 145                 case __SI_POLL >> 16:
 146                         err |= __get_user(to->si_band, &from->si_band);
 147                         err |= __get_user(to->si_fd, &from->si_fd);
 148                         break;
 149                 case __SI_TIMER >> 16:
 150                         err |= __get_user(to->si_tid, &from->si_tid);
 151                         err |= __get_user(to->si_overrun, &from->si_overrun);
 152                         err |= __get_user(to->si_int, &from->si_int);
 153                         break;
 154                 default:
 155                         break;
 156                 }
 157         }
 158         return err;
 159 }
 160
 161 asmlinkage long
 162 sys32_sigaction(int sig, const struct old_sigaction32 __user *act,
 163                  struct old_sigaction32 __user *oact)
 164 {
 165         struct k_sigaction new_ka, old_ka;
 166         unsigned long sa_handler, sa_restorer;
 167         int ret;
 168
 169         if (act) {
 170                 compat_old_sigset_t mask;
 171                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
 172                     __get_user(sa_handler, &act->sa_handler) ||
 173                     __get_user(sa_restorer, &act->sa_restorer))
 174                         return -EFAULT;
 175                 new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
 176                 new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer;
 177                 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 178                 __get_user(mask, &act->sa_mask);
 179                 siginitset(&new_ka.sa.sa_mask, mask);
 180         }
 181
 182         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 183
 184         if (!ret && oact) {
 185                 sa_handler = (unsigned long) old_ka.sa.sa_handler;
 186                 sa_restorer = (unsigned long) old_ka.sa.sa_restorer;
 187                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
 188                     __put_user(sa_handler, &oact->sa_handler) ||
 189                     __put_user(sa_restorer, &oact->sa_restorer))
 190                         return -EFAULT;
 191                 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 192                 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
 193         }
 194
 195         return ret;
 196 }
 197
 198 asmlinkage long
 199 sys32_rt_sigaction(int sig, const struct sigaction32 __user *act,
 200            struct sigaction32 __user *oact,  size_t sigsetsize)
 201 {
 202         struct k_sigaction new_ka, old_ka;
 203         unsigned long sa_handler;
 204         int ret;
 205         compat_sigset_t set32;
 206
 207         /* XXX: Don't preclude handling different sized sigset_t's.  */
 208         if (sigsetsize != sizeof(compat_sigset_t))
 209                 return -EINVAL;
 210
 211         if (act) {
 212                 ret = get_user(sa_handler, &act->sa_handler);
 213                 ret |= __copy_from_user(&set32, &act->sa_mask,
 214                                         sizeof(compat_sigset_t));
 215                 switch (_NSIG_WORDS) {
 216                 case 4: new_ka.sa.sa_mask.sig[3] = set32.sig[6]
 217                                 | (((long)set32.sig[7]) << 32);
 218                 case 3: new_ka.sa.sa_mask.sig[2] = set32.sig[4]
 219                                 | (((long)set32.sig[5]) << 32);
 220                 case 2: new_ka.sa.sa_mask.sig[1] = set32.sig[2]
 221                                 | (((long)set32.sig[3]) << 32);
 222                 case 1: new_ka.sa.sa_mask.sig[0] = set32.sig[0]
 223                                 | (((long)set32.sig[1]) << 32);
 224                 }
 225                 ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
 226
 227                 if (ret)
 228                         return -EFAULT;
 229                 new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
 230         }
 231
 232         ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
 233
 234         if (!ret && oact) {
 235                 switch (_NSIG_WORDS) {
 236                 case 4:
 237                         set32.sig[7] = (old_ka.sa.sa_mask.sig[3] >> 32);
 238                         set32.sig[6] = old_ka.sa.sa_mask.sig[3];
 239                 case 3:
 240                         set32.sig[5] = (old_ka.sa.sa_mask.sig[2] >> 32);
 241                         set32.sig[4] = old_ka.sa.sa_mask.sig[2];
 242                 case 2:
 243                         set32.sig[3] = (old_ka.sa.sa_mask.sig[1] >> 32);
 244                         set32.sig[2] = old_ka.sa.sa_mask.sig[1];
 245                 case 1:
 246                         set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32);
 247                         set32.sig[0] = old_ka.sa.sa_mask.sig[0];
 248                 }
 249                 ret = put_user((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler);
 250                 ret |= __copy_to_user(&oact->sa_mask, &set32,
 251                                       sizeof(compat_sigset_t));
 252                 ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
 253         }
 254
 255         return ret;
 256 }
 257
 258 asmlinkage long
 259 sys32_sigaltstack(const stack_t32 __user *uss, stack_t32 __user *uoss,
 260                                                         struct pt_regs *regs)
 261 {
 262         stack_t kss, koss;
 263         unsigned long ss_sp;
 264         int ret, err = 0;
 265         mm_segment_t old_fs = get_fs();
 266
 267         if (uss) {
 268                 if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
 269                         return -EFAULT;
 270                 err |= __get_user(ss_sp, &uss->ss_sp);
 271                 err |= __get_user(kss.ss_size, &uss->ss_size);
 272                 err |= __get_user(kss.ss_flags, &uss->ss_flags);
 273                 if (err)
 274                         return -EFAULT;
 275                 kss.ss_sp = (void __user *) ss_sp;
 276         }
 277
 278         set_fs (KERNEL_DS);
 279         ret = do_sigaltstack((stack_t __user *) (uss ? &kss : NULL),
 280                              (stack_t __user *) (uoss ? &koss : NULL),
 281                              regs->gprs[15]);
 282         set_fs (old_fs);
 283
 284         if (!ret && uoss) {
 285                 if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
 286                         return -EFAULT;
 287                 ss_sp = (unsigned long) koss.ss_sp;
 288                 err |= __put_user(ss_sp, &uoss->ss_sp);
 289                 err |= __put_user(koss.ss_size, &uoss->ss_size);
 290                 err |= __put_user(koss.ss_flags, &uoss->ss_flags);
 291                 if (err)
 292                         return -EFAULT;
 293         }
 294         return ret;
 295 }
 296
 297 static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
 298 {
 299         _s390_regs_common32 regs32;
 300         int err, i;
 301
 302         regs32.psw.mask = PSW32_MASK_MERGE(PSW32_USER_BITS,
 303                                            (__u32)(regs->psw.mask >> 32));
 304         regs32.psw.addr = PSW32_ADDR_AMODE31 | (__u32) regs->psw.addr;
 305         for (i = 0; i < NUM_GPRS; i++)
 306                 regs32.gprs[i] = (__u32) regs->gprs[i];
 307         save_access_regs(current->thread.acrs);
 308         memcpy(regs32.acrs, current->thread.acrs, sizeof(regs32.acrs));
 309         err = __copy_to_user(&sregs->regs, &regs32, sizeof(regs32));
 310         if (err)
 311                 return err;
 312         save_fp_regs(&current->thread.fp_regs);
 313         /* s390_fp_regs and _s390_fp_regs32 are the same ! */
 314         return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,
 315                               sizeof(_s390_fp_regs32));
 316 }
 317
 318 static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
 319 {
 320         _s390_regs_common32 regs32;
 321         int err, i;
 322
 323         /* Alwys make any pending restarted system call return -EINTR */
 324         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 325
 326         err = __copy_from_user(&regs32, &sregs->regs, sizeof(regs32));
 327         if (err)
 328                 return err;
 329         regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
 330                                         (__u64)regs32.psw.mask << 32);
 331         regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
 332         for (i = 0; i < NUM_GPRS; i++)
 333                 regs->gprs[i] = (__u64) regs32.gprs[i];
 334         memcpy(current->thread.acrs, regs32.acrs, sizeof(current->thread.acrs));
 335         restore_access_regs(current->thread.acrs);
 336
 337         err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,
 338                                sizeof(_s390_fp_regs32));
 339         current->thread.fp_regs.fpc &= FPC_VALID_MASK;
 340         if (err)
 341                 return err;
 342
 343         restore_fp_regs(&current->thread.fp_regs);
 344         regs->trap = -1;        /* disable syscall checks */
 345         return 0;
 346 }
 347
 348 asmlinkage long sys32_sigreturn(struct pt_regs *regs)
 349 {
 350         sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
 351         sigset_t set;
 352
 353         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 354                 goto badframe;
 355         if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
 356                 goto badframe;
 357
 358         sigdelsetmask(&set, ~_BLOCKABLE);
 359         spin_lock_irq(&current->sighand->siglock);
 360         current->blocked = set;
 361         recalc_sigpending();
 362         spin_unlock_irq(&current->sighand->siglock);
 363
 364         if (restore_sigregs32(regs, &frame->sregs))
 365                 goto badframe;
 366
 367         return regs->gprs[2];
 368
 369 badframe:
 370         force_sig(SIGSEGV, current);
 371         return 0;
 372 }
 373
 374 asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
 375 {
 376         rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
 377         sigset_t set;
 378         stack_t st;
 379         __u32 ss_sp;
 380         int err;
 381         mm_segment_t old_fs = get_fs();
 382
 383         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 384                 goto badframe;
 385         if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 386                 goto badframe;
 387
 388         sigdelsetmask(&set, ~_BLOCKABLE);
 389         spin_lock_irq(&current->sighand->siglock);
 390         current->blocked = set;
 391         recalc_sigpending();
 392         spin_unlock_irq(&current->sighand->siglock);
 393
 394         if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
 395                 goto badframe;
 396
 397         err = __get_user(ss_sp, &frame->uc.uc_stack.ss_sp);
 398         st.ss_sp = compat_ptr(ss_sp);
 399         err |= __get_user(st.ss_size, &frame->uc.uc_stack.ss_size);
 400         err |= __get_user(st.ss_flags, &frame->uc.uc_stack.ss_flags);
 401         if (err)
 402                 goto badframe;
 403
 404         set_fs (KERNEL_DS);
 405         do_sigaltstack((stack_t __user *)&st, NULL, regs->gprs[15]);
 406         set_fs (old_fs);
 407
 408         return regs->gprs[2];
 409
 410 badframe:
 411         force_sig(SIGSEGV, current);
 412         return 0;
 413 }
 414
 415 /*
 416  * Set up a signal frame.
 417  */
 418
 419
 420 /*
 421  * Determine which stack to use..
 422  */
 423 static inline void __user *
 424 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
 425 {
 426         unsigned long sp;
 427
 428         /* Default to using normal stack */
 429         sp = (unsigned long) A(regs->gprs[15]);
 430
 431         /* This is the X/Open sanctioned signal stack switching.  */
 432         if (ka->sa.sa_flags & SA_ONSTACK) {
 433                 if (! on_sig_stack(sp))
 434                         sp = current->sas_ss_sp + current->sas_ss_size;
 435         }
 436
 437         /* This is the legacy signal stack switching. */
 438         else if (!user_mode(regs) &&
 439                  !(ka->sa.sa_flags & SA_RESTORER) &&
 440                  ka->sa.sa_restorer) {
 441                 sp = (unsigned long) ka->sa.sa_restorer;
 442         }
 443
 444         return (void __user *)((sp - frame_size) & -8ul);
 445 }
 446
 447 static inline int map_signal(int sig)
 448 {
 449         if (current_thread_info()->exec_domain
 450             && current_thread_info()->exec_domain->signal_invmap
 451             && sig < 32)
 452                 return current_thread_info()->exec_domain->signal_invmap[sig];
 453         else
 454                 return sig;
 455 }
 456
 457 static int setup_frame32(int sig, struct k_sigaction *ka,
 458                         sigset_t *set, struct pt_regs * regs)
 459 {
 460         sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));
 461         if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32)))
 462                 goto give_sigsegv;
 463
 464         if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))
 465                 goto give_sigsegv;
 466
 467         if (save_sigregs32(regs, &frame->sregs))
 468                 goto give_sigsegv;
 469         if (__put_user((unsigned long) &frame->sregs, &frame->sc.sregs))
 470                 goto give_sigsegv;
 471
 472         /* Set up to return from userspace.  If provided, use a stub
 473            already in userspace.  */
 474         if (ka->sa.sa_flags & SA_RESTORER) {
 475                 regs->gprs[14] = (__u64) ka->sa.sa_restorer;
 476         } else {
 477                 regs->gprs[14] = (__u64) frame->retcode;
 478                 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
 479                                (u16 __user *)(frame->retcode)))
 480                         goto give_sigsegv;
 481         }
 482
 483         /* Set up backchain. */
 484         if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
 485                 goto give_sigsegv;
 486
 487         /* Set up registers for signal handler */
 488         regs->gprs[15] = (__u64) frame;
 489         regs->psw.addr = (__u64) ka->sa.sa_handler;
 490
 491         regs->gprs[2] = map_signal(sig);
 492         regs->gprs[3] = (__u64) &frame->sc;
 493
 494         /* We forgot to include these in the sigcontext.
 495            To avoid breaking binary compatibility, they are passed as args. */
 496         regs->gprs[4] = current->thread.trap_no;
 497         regs->gprs[5] = current->thread.prot_addr;
 498
 499         /* Place signal number on stack to allow backtrace from handler.  */
 500         if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
 501                 goto give_sigsegv;
 502         return 0;
 503
 504 give_sigsegv:
 505         force_sigsegv(sig, current);
 506         return -EFAULT;
 507 }
 508
 509 static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
 510                            sigset_t *set, struct pt_regs * regs)
 511 {
 512         int err = 0;
 513         rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));
 514         if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32)))
 515                 goto give_sigsegv;
 516
 517         if (copy_siginfo_to_user32(&frame->info, info))
 518                 goto give_sigsegv;
 519
 520         /* Create the ucontext.  */
 521         err |= __put_user(0, &frame->uc.uc_flags);
 522         err |= __put_user(0, &frame->uc.uc_link);
 523         err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 524         err |= __put_user(sas_ss_flags(regs->gprs[15]),
 525                           &frame->uc.uc_stack.ss_flags);
 526         err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 527         err |= save_sigregs32(regs, &frame->uc.uc_mcontext);
 528         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 529         if (err)
 530                 goto give_sigsegv;
 531
 532         /* Set up to return from userspace.  If provided, use a stub
 533            already in userspace.  */
 534         if (ka->sa.sa_flags & SA_RESTORER) {
 535                 regs->gprs[14] = (__u64) ka->sa.sa_restorer;
 536         } else {
 537                 regs->gprs[14] = (__u64) frame->retcode;
 538                 err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
 539                                   (u16 __user *)(frame->retcode));
 540         }
 541
 542         /* Set up backchain. */
 543         if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
 544                 goto give_sigsegv;
 545
 546         /* Set up registers for signal handler */
 547         regs->gprs[15] = (__u64) frame;
 548         regs->psw.addr = (__u64) ka->sa.sa_handler;
 549
 550         regs->gprs[2] = map_signal(sig);
 551         regs->gprs[3] = (__u64) &frame->info;
 552         regs->gprs[4] = (__u64) &frame->uc;
 553         return 0;
 554
 555 give_sigsegv:
 556         force_sigsegv(sig, current);
 557         return -EFAULT;
 558 }
 559
 560 /*
 561  * OK, we're invoking a handler
 562  */
 563
 564 int
 565 handle_signal32(unsigned long sig, struct k_sigaction *ka,
 566                 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
 567 {
 568         int ret;
 569
 570         /* Set up the stack frame */
 571         if (ka->sa.sa_flags & SA_SIGINFO)
 572                 ret = setup_rt_frame32(sig, ka, info, oldset, regs);
 573         else
 574                 ret = setup_frame32(sig, ka, oldset, regs);
 575
 576         if (ret == 0) {
 577                 spin_lock_irq(&current->sighand->siglock);
 578                 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 579                 if (!(ka->sa.sa_flags & SA_NODEFER))
 580                         sigaddset(&current->blocked,sig);
 581                 recalc_sigpending();
 582                 spin_unlock_irq(&current->sighand->siglock);
 583         }
 584         return ret;
 585 }
 586