arch/arm64/kernel/signal32.c

   1 /*
   2  * Based on arch/arm/kernel/signal.c
   3  *
   4  * Copyright (C) 1995-2009 Russell King
   5  * Copyright (C) 2012 ARM Ltd.
   6  * Modified by Will Deacon <will.deacon@arm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <linux/compat.h>
  22 #include <linux/signal.h>
  23 #include <linux/syscalls.h>
  24 #include <linux/ratelimit.h>
  25
  26 #include <asm/esr.h>
  27 #include <asm/fpsimd.h>
  28 #include <asm/signal32.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unistd.h>
  31
  32 struct compat_sigcontext {
  33         /* We always set these two fields to 0 */
  34         compat_ulong_t                  trap_no;
  35         compat_ulong_t                  error_code;
  36
  37         compat_ulong_t                  oldmask;
  38         compat_ulong_t                  arm_r0;
  39         compat_ulong_t                  arm_r1;
  40         compat_ulong_t                  arm_r2;
  41         compat_ulong_t                  arm_r3;
  42         compat_ulong_t                  arm_r4;
  43         compat_ulong_t                  arm_r5;
  44         compat_ulong_t                  arm_r6;
  45         compat_ulong_t                  arm_r7;
  46         compat_ulong_t                  arm_r8;
  47         compat_ulong_t                  arm_r9;
  48         compat_ulong_t                  arm_r10;
  49         compat_ulong_t                  arm_fp;
  50         compat_ulong_t                  arm_ip;
  51         compat_ulong_t                  arm_sp;
  52         compat_ulong_t                  arm_lr;
  53         compat_ulong_t                  arm_pc;
  54         compat_ulong_t                  arm_cpsr;
  55         compat_ulong_t                  fault_address;
  56 };
  57
  58 struct compat_ucontext {
  59         compat_ulong_t                  uc_flags;
  60         compat_uptr_t                   uc_link;
  61         compat_stack_t                  uc_stack;
  62         struct compat_sigcontext        uc_mcontext;
  63         compat_sigset_t                 uc_sigmask;
  64         int             __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
  65         compat_ulong_t  uc_regspace[128] __attribute__((__aligned__(8)));
  66 };
  67
  68 struct compat_vfp_sigframe {
  69         compat_ulong_t  magic;
  70         compat_ulong_t  size;
  71         struct compat_user_vfp {
  72                 compat_u64      fpregs[32];
  73                 compat_ulong_t  fpscr;
  74         } ufp;
  75         struct compat_user_vfp_exc {
  76                 compat_ulong_t  fpexc;
  77                 compat_ulong_t  fpinst;
  78                 compat_ulong_t  fpinst2;
  79         } ufp_exc;
  80 } __attribute__((__aligned__(8)));
  81
  82 #define VFP_MAGIC               0x56465001
  83 #define VFP_STORAGE_SIZE        sizeof(struct compat_vfp_sigframe)
  84
  85 #define FSR_WRITE_SHIFT         (11)
  86
  87 struct compat_aux_sigframe {
  88         struct compat_vfp_sigframe      vfp;
  89
  90         /* Something that isn't a valid magic number for any coprocessor.  */
  91         unsigned long                   end_magic;
  92 } __attribute__((__aligned__(8)));
  93
  94 struct compat_sigframe {
  95         struct compat_ucontext  uc;
  96         compat_ulong_t          retcode[2];
  97 };
  98
  99 struct compat_rt_sigframe {
 100         struct compat_siginfo info;
 101         struct compat_sigframe sig;
 102 };
 103
 104 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 105
 106 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
 107 {
 108         compat_sigset_t cset;
 109
 110         cset.sig[0] = set->sig[0] & 0xffffffffull;
 111         cset.sig[1] = set->sig[0] >> 32;
 112
 113         return copy_to_user(uset, &cset, sizeof(*uset));
 114 }
 115
 116 static inline int get_sigset_t(sigset_t *set,
 117                                const compat_sigset_t __user *uset)
 118 {
 119         compat_sigset_t s32;
 120
 121         if (copy_from_user(&s32, uset, sizeof(*uset)))
 122                 return -EFAULT;
 123
 124         set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
 125         return 0;
 126 }
 127
 128 int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
 129 {
 130         int err;
 131
 132         if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
 133                 return -EFAULT;
 134
 135         /* If you change siginfo_t structure, please be sure
 136          * this code is fixed accordingly.
 137          * It should never copy any pad contained in the structure
 138          * to avoid security leaks, but must copy the generic
 139          * 3 ints plus the relevant union member.
 140          * This routine must convert siginfo from 64bit to 32bit as well
 141          * at the same time.
 142          */
 143         err = __put_user(from->si_signo, &to->si_signo);
 144         err |= __put_user(from->si_errno, &to->si_errno);
 145         err |= __put_user((short)from->si_code, &to->si_code);
 146         if (from->si_code < 0)
 147                 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
 148                                       SI_PAD_SIZE);
 149         else switch (from->si_code & __SI_MASK) {
 150         case __SI_KILL:
 151                 err |= __put_user(from->si_pid, &to->si_pid);
 152                 err |= __put_user(from->si_uid, &to->si_uid);
 153                 break;
 154         case __SI_TIMER:
 155                  err |= __put_user(from->si_tid, &to->si_tid);
 156                  err |= __put_user(from->si_overrun, &to->si_overrun);
 157                  err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
 158                                    &to->si_ptr);
 159                 break;
 160         case __SI_POLL:
 161                 err |= __put_user(from->si_band, &to->si_band);
 162                 err |= __put_user(from->si_fd, &to->si_fd);
 163                 break;
 164         case __SI_FAULT:
 165                 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
 166                                   &to->si_addr);
 167 #ifdef BUS_MCEERR_AO
 168                 /*
 169                  * Other callers might not initialize the si_lsb field,
 170                  * so check explicitely for the right codes here.
 171                  */
 172                 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
 173                         err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
 174 #endif
 175                 break;
 176         case __SI_CHLD:
 177                 err |= __put_user(from->si_pid, &to->si_pid);
 178                 err |= __put_user(from->si_uid, &to->si_uid);
 179                 err |= __put_user(from->si_status, &to->si_status);
 180                 err |= __put_user(from->si_utime, &to->si_utime);
 181                 err |= __put_user(from->si_stime, &to->si_stime);
 182                 break;
 183         case __SI_RT: /* This is not generated by the kernel as of now. */
 184         case __SI_MESGQ: /* But this is */
 185                 err |= __put_user(from->si_pid, &to->si_pid);
 186                 err |= __put_user(from->si_uid, &to->si_uid);
 187                 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
 188                 break;
 189         case __SI_SYS:
 190                 err |= __put_user((compat_uptr_t)(unsigned long)
 191                                 from->si_call_addr, &to->si_call_addr);
 192                 err |= __put_user(from->si_syscall, &to->si_syscall);
 193                 err |= __put_user(from->si_arch, &to->si_arch);
 194                 break;
 195         default: /* this is just in case for now ... */
 196                 err |= __put_user(from->si_pid, &to->si_pid);
 197                 err |= __put_user(from->si_uid, &to->si_uid);
 198                 break;
 199         }
 200         return err;
 201 }
 202
 203 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 204 {
 205         memset(to, 0, sizeof *to);
 206
 207         if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
 208             copy_from_user(to->_sifields._pad,
 209                            from->_sifields._pad, SI_PAD_SIZE))
 210                 return -EFAULT;
 211
 212         return 0;
 213 }
 214
 215 /*
 216  * VFP save/restore code.
 217  */
 218 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
 219 {
 220         struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
 221         compat_ulong_t magic = VFP_MAGIC;
 222         compat_ulong_t size = VFP_STORAGE_SIZE;
 223         compat_ulong_t fpscr, fpexc;
 224         int err = 0;
 225
 226         /*
 227          * Save the hardware registers to the fpsimd_state structure.
 228          * Note that this also saves V16-31, which aren't visible
 229          * in AArch32.
 230          */
 231         fpsimd_preserve_current_state();
 232
 233         /* Place structure header on the stack */
 234         __put_user_error(magic, &frame->magic, err);
 235         __put_user_error(size, &frame->size, err);
 236
 237         /*
 238          * Now copy the FP registers. Since the registers are packed,
 239          * we can copy the prefix we want (V0-V15) as it is.
 240          * FIXME: Won't work if big endian.
 241          */
 242         err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
 243                               sizeof(frame->ufp.fpregs));
 244
 245         /* Create an AArch32 fpscr from the fpsr and the fpcr. */
 246         fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
 247                 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
 248         __put_user_error(fpscr, &frame->ufp.fpscr, err);
 249
 250         /*
 251          * The exception register aren't available so we fake up a
 252          * basic FPEXC and zero everything else.
 253          */
 254         fpexc = (1 << 30);
 255         __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
 256         __put_user_error(0, &frame->ufp_exc.fpinst, err);
 257         __put_user_error(0, &frame->ufp_exc.fpinst2, err);
 258
 259         return err ? -EFAULT : 0;
 260 }
 261
 262 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
 263 {
 264         struct fpsimd_state fpsimd;
 265         compat_ulong_t magic = VFP_MAGIC;
 266         compat_ulong_t size = VFP_STORAGE_SIZE;
 267         compat_ulong_t fpscr;
 268         int err = 0;
 269
 270         __get_user_error(magic, &frame->magic, err);
 271         __get_user_error(size, &frame->size, err);
 272
 273         if (err)
 274                 return -EFAULT;
 275         if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
 276                 return -EINVAL;
 277
 278         /*
 279          * Copy the FP registers into the start of the fpsimd_state.
 280          * FIXME: Won't work if big endian.
 281          */
 282         err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
 283                                 sizeof(frame->ufp.fpregs));
 284
 285         /* Extract the fpsr and the fpcr from the fpscr */
 286         __get_user_error(fpscr, &frame->ufp.fpscr, err);
 287         fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 288         fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 289
 290         /*
 291          * We don't need to touch the exception register, so
 292          * reload the hardware state.
 293          */
 294         if (!err)
 295                 fpsimd_update_current_state(&fpsimd);
 296
 297         return err ? -EFAULT : 0;
 298 }
 299
 300 static int compat_restore_sigframe(struct pt_regs *regs,
 301                                    struct compat_sigframe __user *sf)
 302 {
 303         int err;
 304         sigset_t set;
 305         struct compat_aux_sigframe __user *aux;
 306
 307         err = get_sigset_t(&set, &sf->uc.uc_sigmask);
 308         if (err == 0) {
 309                 sigdelsetmask(&set, ~_BLOCKABLE);
 310                 set_current_blocked(&set);
 311         }
 312
 313         __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
 314         __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
 315         __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
 316         __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
 317         __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
 318         __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
 319         __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
 320         __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
 321         __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
 322         __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
 323         __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
 324         __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
 325         __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
 326         __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
 327         __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
 328         __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
 329         __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
 330
 331         /*
 332          * Avoid compat_sys_sigreturn() restarting.
 333          */
 334         regs->syscallno = ~0UL;
 335
 336         err |= !valid_user_regs(&regs->user_regs);
 337
 338         aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
 339         if (err == 0)
 340                 err |= compat_restore_vfp_context(&aux->vfp);
 341
 342         return err;
 343 }
 344
 345 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
 346 {
 347         struct compat_sigframe __user *frame;
 348
 349         /* Always make any pending restarted system calls return -EINTR */
 350         current->restart_block.fn = do_no_restart_syscall;
 351
 352         /*
 353          * Since we stacked the signal on a 64-bit boundary,
 354          * then 'sp' should be word aligned here.  If it's
 355          * not, then the user is trying to mess with us.
 356          */
 357         if (regs->compat_sp & 7)
 358                 goto badframe;
 359
 360         frame = (struct compat_sigframe __user *)regs->compat_sp;
 361
 362         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
 363                 goto badframe;
 364
 365         if (compat_restore_sigframe(regs, frame))
 366                 goto badframe;
 367
 368         return regs->regs[0];
 369
 370 badframe:
 371         if (show_unhandled_signals)
 372                 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
 373                                     current->comm, task_pid_nr(current), __func__,
 374                                     regs->pc, regs->sp);
 375         force_sig(SIGSEGV, current);
 376         return 0;
 377 }
 378
 379 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
 380 {
 381         struct compat_rt_sigframe __user *frame;
 382
 383         /* Always make any pending restarted system calls return -EINTR */
 384         current->restart_block.fn = do_no_restart_syscall;
 385
 386         /*
 387          * Since we stacked the signal on a 64-bit boundary,
 388          * then 'sp' should be word aligned here.  If it's
 389          * not, then the user is trying to mess with us.
 390          */
 391         if (regs->compat_sp & 7)
 392                 goto badframe;
 393
 394         frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
 395
 396         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
 397                 goto badframe;
 398
 399         if (compat_restore_sigframe(regs, &frame->sig))
 400                 goto badframe;
 401
 402         if (compat_restore_altstack(&frame->sig.uc.uc_stack))
 403                 goto badframe;
 404
 405         return regs->regs[0];
 406
 407 badframe:
 408         if (show_unhandled_signals)
 409                 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
 410                                     current->comm, task_pid_nr(current), __func__,
 411                                     regs->pc, regs->sp);
 412         force_sig(SIGSEGV, current);
 413         return 0;
 414 }
 415
 416 static void __user *compat_get_sigframe(struct ksignal *ksig,
 417                                         struct pt_regs *regs,
 418                                         int framesize)
 419 {
 420         compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
 421         void __user *frame;
 422
 423         /*
 424          * ATPCS B01 mandates 8-byte alignment
 425          */
 426         frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
 427
 428         /*
 429          * Check that we can actually write to the signal frame.
 430          */
 431         if (!access_ok(VERIFY_WRITE, frame, framesize))
 432                 frame = NULL;
 433
 434         return frame;
 435 }
 436
 437 static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 438                                 compat_ulong_t __user *rc, void __user *frame,
 439                                 int usig)
 440 {
 441         compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
 442         compat_ulong_t retcode;
 443         compat_ulong_t spsr = regs->pstate & ~(PSR_f | COMPAT_PSR_E_BIT);
 444         int thumb;
 445
 446         /* Check if the handler is written for ARM or Thumb */
 447         thumb = handler & 1;
 448
 449         if (thumb)
 450                 spsr |= COMPAT_PSR_T_BIT;
 451         else
 452                 spsr &= ~COMPAT_PSR_T_BIT;
 453
 454         /* The IT state must be cleared for both ARM and Thumb-2 */
 455         spsr &= ~COMPAT_PSR_IT_MASK;
 456
 457         /* Restore the original endianness */
 458         spsr |= COMPAT_PSR_ENDSTATE;
 459
 460         if (ka->sa.sa_flags & SA_RESTORER) {
 461                 retcode = ptr_to_compat(ka->sa.sa_restorer);
 462         } else {
 463                 /* Set up sigreturn pointer */
 464                 unsigned int idx = thumb << 1;
 465
 466                 if (ka->sa.sa_flags & SA_SIGINFO)
 467                         idx += 3;
 468
 469                 retcode = AARCH32_VECTORS_BASE +
 470                           AARCH32_KERN_SIGRET_CODE_OFFSET +
 471                           (idx << 2) + thumb;
 472         }
 473
 474         regs->regs[0]   = usig;
 475         regs->compat_sp = ptr_to_compat(frame);
 476         regs->compat_lr = retcode;
 477         regs->pc        = handler;
 478         regs->pstate    = spsr;
 479 }
 480
 481 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
 482                                  struct pt_regs *regs, sigset_t *set)
 483 {
 484         struct compat_aux_sigframe __user *aux;
 485         int err = 0;
 486
 487         __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
 488         __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
 489         __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
 490         __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
 491         __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
 492         __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
 493         __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
 494         __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
 495         __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
 496         __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
 497         __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
 498         __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
 499         __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
 500         __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
 501         __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
 502         __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
 503         __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
 504
 505         __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
 506         /* set the compat FSR WnR */
 507         __put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
 508                          FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
 509         __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
 510         __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
 511
 512         err |= put_sigset_t(&sf->uc.uc_sigmask, set);
 513
 514         aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
 515
 516         if (err == 0)
 517                 err |= compat_preserve_vfp_context(&aux->vfp);
 518         __put_user_error(0, &aux->end_magic, err);
 519
 520         return err;
 521 }
 522
 523 /*
 524  * 32-bit signal handling routines called from signal.c
 525  */
 526 int compat_setup_rt_frame(int usig, struct ksignal *ksig,
 527                           sigset_t *set, struct pt_regs *regs)
 528 {
 529         struct compat_rt_sigframe __user *frame;
 530         int err = 0;
 531
 532         frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
 533
 534         if (!frame)
 535                 return 1;
 536
 537         err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
 538
 539         __put_user_error(0, &frame->sig.uc.uc_flags, err);
 540         __put_user_error(0, &frame->sig.uc.uc_link, err);
 541
 542         err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
 543
 544         err |= compat_setup_sigframe(&frame->sig, regs, set);
 545
 546         if (err == 0) {
 547                 compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
 548                 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
 549                 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
 550         }
 551
 552         return err;
 553 }
 554
 555 int compat_setup_frame(int usig, struct ksignal *ksig, sigset_t *set,
 556                        struct pt_regs *regs)
 557 {
 558         struct compat_sigframe __user *frame;
 559         int err = 0;
 560
 561         frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
 562
 563         if (!frame)
 564                 return 1;
 565
 566         __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
 567
 568         err |= compat_setup_sigframe(frame, regs, set);
 569         if (err == 0)
 570                 compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
 571
 572         return err;
 573 }
 574
 575 void compat_setup_restart_syscall(struct pt_regs *regs)
 576 {
 577        regs->regs[7] = __NR_compat_restart_syscall;
 578 }