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/fpsimd.h>
  27 #include <asm/signal32.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/unistd32.h>
  30
  31 struct compat_sigcontext {
  32         /* We always set these two fields to 0 */
  33         compat_ulong_t                  trap_no;
  34         compat_ulong_t                  error_code;
  35
  36         compat_ulong_t                  oldmask;
  37         compat_ulong_t                  arm_r0;
  38         compat_ulong_t                  arm_r1;
  39         compat_ulong_t                  arm_r2;
  40         compat_ulong_t                  arm_r3;
  41         compat_ulong_t                  arm_r4;
  42         compat_ulong_t                  arm_r5;
  43         compat_ulong_t                  arm_r6;
  44         compat_ulong_t                  arm_r7;
  45         compat_ulong_t                  arm_r8;
  46         compat_ulong_t                  arm_r9;
  47         compat_ulong_t                  arm_r10;
  48         compat_ulong_t                  arm_fp;
  49         compat_ulong_t                  arm_ip;
  50         compat_ulong_t                  arm_sp;
  51         compat_ulong_t                  arm_lr;
  52         compat_ulong_t                  arm_pc;
  53         compat_ulong_t                  arm_cpsr;
  54         compat_ulong_t                  fault_address;
  55 };
  56
  57 struct compat_ucontext {
  58         compat_ulong_t                  uc_flags;
  59         compat_uptr_t                   uc_link;
  60         compat_stack_t                  uc_stack;
  61         struct compat_sigcontext        uc_mcontext;
  62         compat_sigset_t                 uc_sigmask;
  63         int             __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
  64         compat_ulong_t  uc_regspace[128] __attribute__((__aligned__(8)));
  65 };
  66
  67 struct compat_vfp_sigframe {
  68         compat_ulong_t  magic;
  69         compat_ulong_t  size;
  70         struct compat_user_vfp {
  71                 compat_u64      fpregs[32];
  72                 compat_ulong_t  fpscr;
  73         } ufp;
  74         struct compat_user_vfp_exc {
  75                 compat_ulong_t  fpexc;
  76                 compat_ulong_t  fpinst;
  77                 compat_ulong_t  fpinst2;
  78         } ufp_exc;
  79 } __attribute__((__aligned__(8)));
  80
  81 #define VFP_MAGIC               0x56465001
  82 #define VFP_STORAGE_SIZE        sizeof(struct compat_vfp_sigframe)
  83
  84 struct compat_aux_sigframe {
  85         struct compat_vfp_sigframe      vfp;
  86
  87         /* Something that isn't a valid magic number for any coprocessor.  */
  88         unsigned long                   end_magic;
  89 } __attribute__((__aligned__(8)));
  90
  91 struct compat_sigframe {
  92         struct compat_ucontext  uc;
  93         compat_ulong_t          retcode[2];
  94 };
  95
  96 struct compat_rt_sigframe {
  97         struct compat_siginfo info;
  98         struct compat_sigframe sig;
  99 };
 100
 101 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 102
 103 /*
 104  * For ARM syscalls, the syscall number has to be loaded into r7.
 105  * We do not support an OABI userspace.
 106  */
 107 #define MOV_R7_NR_SIGRETURN     (0xe3a07000 | __NR_compat_sigreturn)
 108 #define SVC_SYS_SIGRETURN       (0xef000000 | __NR_compat_sigreturn)
 109 #define MOV_R7_NR_RT_SIGRETURN  (0xe3a07000 | __NR_compat_rt_sigreturn)
 110 #define SVC_SYS_RT_SIGRETURN    (0xef000000 | __NR_compat_rt_sigreturn)
 111
 112 /*
 113  * For Thumb syscalls, we also pass the syscall number via r7. We therefore
 114  * need two 16-bit instructions.
 115  */
 116 #define SVC_THUMB_SIGRETURN     (((0xdf00 | __NR_compat_sigreturn) << 16) | \
 117                                    0x2700 | __NR_compat_sigreturn)
 118 #define SVC_THUMB_RT_SIGRETURN  (((0xdf00 | __NR_compat_rt_sigreturn) << 16) | \
 119                                    0x2700 | __NR_compat_rt_sigreturn)
 120
 121 const compat_ulong_t aarch32_sigret_code[6] = {
 122         /*
 123          * AArch32 sigreturn code.
 124          * We don't construct an OABI SWI - instead we just set the imm24 field
 125          * to the EABI syscall number so that we create a sane disassembly.
 126          */
 127         MOV_R7_NR_SIGRETURN,    SVC_SYS_SIGRETURN,    SVC_THUMB_SIGRETURN,
 128         MOV_R7_NR_RT_SIGRETURN, SVC_SYS_RT_SIGRETURN, SVC_THUMB_RT_SIGRETURN,
 129 };
 130
 131 static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
 132 {
 133         compat_sigset_t cset;
 134
 135         cset.sig[0] = set->sig[0] & 0xffffffffull;
 136         cset.sig[1] = set->sig[0] >> 32;
 137
 138         return copy_to_user(uset, &cset, sizeof(*uset));
 139 }
 140
 141 static inline int get_sigset_t(sigset_t *set,
 142                                const compat_sigset_t __user *uset)
 143 {
 144         compat_sigset_t s32;
 145
 146         if (copy_from_user(&s32, uset, sizeof(*uset)))
 147                 return -EFAULT;
 148
 149         set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
 150         return 0;
 151 }
 152
 153 int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
 154 {
 155         int err;
 156
 157         if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
 158                 return -EFAULT;
 159
 160         /* If you change siginfo_t structure, please be sure
 161          * this code is fixed accordingly.
 162          * It should never copy any pad contained in the structure
 163          * to avoid security leaks, but must copy the generic
 164          * 3 ints plus the relevant union member.
 165          * This routine must convert siginfo from 64bit to 32bit as well
 166          * at the same time.
 167          */
 168         err = __put_user(from->si_signo, &to->si_signo);
 169         err |= __put_user(from->si_errno, &to->si_errno);
 170         err |= __put_user((short)from->si_code, &to->si_code);
 171         if (from->si_code < 0)
 172                 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
 173                                       SI_PAD_SIZE);
 174         else switch (from->si_code & __SI_MASK) {
 175         case __SI_KILL:
 176                 err |= __put_user(from->si_pid, &to->si_pid);
 177                 err |= __put_user(from->si_uid, &to->si_uid);
 178                 break;
 179         case __SI_TIMER:
 180                  err |= __put_user(from->si_tid, &to->si_tid);
 181                  err |= __put_user(from->si_overrun, &to->si_overrun);
 182                  err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
 183                                    &to->si_ptr);
 184                 break;
 185         case __SI_POLL:
 186                 err |= __put_user(from->si_band, &to->si_band);
 187                 err |= __put_user(from->si_fd, &to->si_fd);
 188                 break;
 189         case __SI_FAULT:
 190                 err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
 191                                   &to->si_addr);
 192 #ifdef BUS_MCEERR_AO
 193                 /*
 194                  * Other callers might not initialize the si_lsb field,
 195                  * so check explicitely for the right codes here.
 196                  */
 197                 if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
 198                         err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
 199 #endif
 200                 break;
 201         case __SI_CHLD:
 202                 err |= __put_user(from->si_pid, &to->si_pid);
 203                 err |= __put_user(from->si_uid, &to->si_uid);
 204                 err |= __put_user(from->si_status, &to->si_status);
 205                 err |= __put_user(from->si_utime, &to->si_utime);
 206                 err |= __put_user(from->si_stime, &to->si_stime);
 207                 break;
 208         case __SI_RT: /* This is not generated by the kernel as of now. */
 209         case __SI_MESGQ: /* But this is */
 210                 err |= __put_user(from->si_pid, &to->si_pid);
 211                 err |= __put_user(from->si_uid, &to->si_uid);
 212                 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
 213                 break;
 214         default: /* this is just in case for now ... */
 215                 err |= __put_user(from->si_pid, &to->si_pid);
 216                 err |= __put_user(from->si_uid, &to->si_uid);
 217                 break;
 218         }
 219         return err;
 220 }
 221
 222 int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
 223 {
 224         memset(to, 0, sizeof *to);
 225
 226         if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
 227             copy_from_user(to->_sifields._pad,
 228                            from->_sifields._pad, SI_PAD_SIZE))
 229                 return -EFAULT;
 230
 231         return 0;
 232 }
 233
 234 /*
 235  * VFP save/restore code.
 236  */
 237 static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
 238 {
 239         struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
 240         compat_ulong_t magic = VFP_MAGIC;
 241         compat_ulong_t size = VFP_STORAGE_SIZE;
 242         compat_ulong_t fpscr, fpexc;
 243         int err = 0;
 244
 245         /*
 246          * Save the hardware registers to the fpsimd_state structure.
 247          * Note that this also saves V16-31, which aren't visible
 248          * in AArch32.
 249          */
 250         fpsimd_save_state(fpsimd);
 251
 252         /* Place structure header on the stack */
 253         __put_user_error(magic, &frame->magic, err);
 254         __put_user_error(size, &frame->size, err);
 255
 256         /*
 257          * Now copy the FP registers. Since the registers are packed,
 258          * we can copy the prefix we want (V0-V15) as it is.
 259          * FIXME: Won't work if big endian.
 260          */
 261         err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
 262                               sizeof(frame->ufp.fpregs));
 263
 264         /* Create an AArch32 fpscr from the fpsr and the fpcr. */
 265         fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
 266                 (fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
 267         __put_user_error(fpscr, &frame->ufp.fpscr, err);
 268
 269         /*
 270          * The exception register aren't available so we fake up a
 271          * basic FPEXC and zero everything else.
 272          */
 273         fpexc = (1 << 30);
 274         __put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
 275         __put_user_error(0, &frame->ufp_exc.fpinst, err);
 276         __put_user_error(0, &frame->ufp_exc.fpinst2, err);
 277
 278         return err ? -EFAULT : 0;
 279 }
 280
 281 static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
 282 {
 283         struct fpsimd_state fpsimd;
 284         compat_ulong_t magic = VFP_MAGIC;
 285         compat_ulong_t size = VFP_STORAGE_SIZE;
 286         compat_ulong_t fpscr;
 287         int err = 0;
 288
 289         __get_user_error(magic, &frame->magic, err);
 290         __get_user_error(size, &frame->size, err);
 291
 292         if (err)
 293                 return -EFAULT;
 294         if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
 295                 return -EINVAL;
 296
 297         /*
 298          * Copy the FP registers into the start of the fpsimd_state.
 299          * FIXME: Won't work if big endian.
 300          */
 301         err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
 302                                 sizeof(frame->ufp.fpregs));
 303
 304         /* Extract the fpsr and the fpcr from the fpscr */
 305         __get_user_error(fpscr, &frame->ufp.fpscr, err);
 306         fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 307         fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 308
 309         /*
 310          * We don't need to touch the exception register, so
 311          * reload the hardware state.
 312          */
 313         if (!err) {
 314                 preempt_disable();
 315                 fpsimd_load_state(&fpsimd);
 316                 preempt_enable();
 317         }
 318
 319         return err ? -EFAULT : 0;
 320 }
 321
 322 static int compat_restore_sigframe(struct pt_regs *regs,
 323                                    struct compat_sigframe __user *sf)
 324 {
 325         int err;
 326         sigset_t set;
 327         struct compat_aux_sigframe __user *aux;
 328
 329         err = get_sigset_t(&set, &sf->uc.uc_sigmask);
 330         if (err == 0) {
 331                 sigdelsetmask(&set, ~_BLOCKABLE);
 332                 set_current_blocked(&set);
 333         }
 334
 335         __get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
 336         __get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
 337         __get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
 338         __get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
 339         __get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
 340         __get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
 341         __get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
 342         __get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
 343         __get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
 344         __get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
 345         __get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
 346         __get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
 347         __get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
 348         __get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
 349         __get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
 350         __get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
 351         __get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
 352
 353         /*
 354          * Avoid compat_sys_sigreturn() restarting.
 355          */
 356         regs->syscallno = ~0UL;
 357
 358         err |= !valid_user_regs(&regs->user_regs);
 359
 360         aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
 361         if (err == 0)
 362                 err |= compat_restore_vfp_context(&aux->vfp);
 363
 364         return err;
 365 }
 366
 367 asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
 368 {
 369         struct compat_sigframe __user *frame;
 370
 371         /* Always make any pending restarted system calls return -EINTR */
 372         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 373
 374         /*
 375          * Since we stacked the signal on a 64-bit boundary,
 376          * then 'sp' should be word aligned here.  If it's
 377          * not, then the user is trying to mess with us.
 378          */
 379         if (regs->compat_sp & 7)
 380                 goto badframe;
 381
 382         frame = (struct compat_sigframe __user *)regs->compat_sp;
 383
 384         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
 385                 goto badframe;
 386
 387         if (compat_restore_sigframe(regs, frame))
 388                 goto badframe;
 389
 390         return regs->regs[0];
 391
 392 badframe:
 393         if (show_unhandled_signals)
 394                 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
 395                                     current->comm, task_pid_nr(current), __func__,
 396                                     regs->pc, regs->sp);
 397         force_sig(SIGSEGV, current);
 398         return 0;
 399 }
 400
 401 asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
 402 {
 403         struct compat_rt_sigframe __user *frame;
 404
 405         /* Always make any pending restarted system calls return -EINTR */
 406         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 407
 408         /*
 409          * Since we stacked the signal on a 64-bit boundary,
 410          * then 'sp' should be word aligned here.  If it's
 411          * not, then the user is trying to mess with us.
 412          */
 413         if (regs->compat_sp & 7)
 414                 goto badframe;
 415
 416         frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
 417
 418         if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
 419                 goto badframe;
 420
 421         if (compat_restore_sigframe(regs, &frame->sig))
 422                 goto badframe;
 423
 424         if (compat_restore_altstack(&frame->sig.uc.uc_stack))
 425                 goto badframe;
 426
 427         return regs->regs[0];
 428
 429 badframe:
 430         if (show_unhandled_signals)
 431                 pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
 432                                     current->comm, task_pid_nr(current), __func__,
 433                                     regs->pc, regs->sp);
 434         force_sig(SIGSEGV, current);
 435         return 0;
 436 }
 437
 438 static void __user *compat_get_sigframe(struct k_sigaction *ka,
 439                                         struct pt_regs *regs,
 440                                         int framesize)
 441 {
 442         compat_ulong_t sp = regs->compat_sp;
 443         void __user *frame;
 444
 445         /*
 446          * This is the X/Open sanctioned signal stack switching.
 447          */
 448         if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
 449                 sp = current->sas_ss_sp + current->sas_ss_size;
 450
 451         /*
 452          * ATPCS B01 mandates 8-byte alignment
 453          */
 454         frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
 455
 456         /*
 457          * Check that we can actually write to the signal frame.
 458          */
 459         if (!access_ok(VERIFY_WRITE, frame, framesize))
 460                 frame = NULL;
 461
 462         return frame;
 463 }
 464
 465 static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 466                                 compat_ulong_t __user *rc, void __user *frame,
 467                                 int usig)
 468 {
 469         compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
 470         compat_ulong_t retcode;
 471         compat_ulong_t spsr = regs->pstate & ~PSR_f;
 472         int thumb;
 473
 474         /* Check if the handler is written for ARM or Thumb */
 475         thumb = handler & 1;
 476
 477         if (thumb) {
 478                 spsr |= COMPAT_PSR_T_BIT;
 479                 spsr &= ~COMPAT_PSR_IT_MASK;
 480         } else {
 481                 spsr &= ~COMPAT_PSR_T_BIT;
 482         }
 483
 484         if (ka->sa.sa_flags & SA_RESTORER) {
 485                 retcode = ptr_to_compat(ka->sa.sa_restorer);
 486         } else {
 487                 /* Set up sigreturn pointer */
 488                 unsigned int idx = thumb << 1;
 489
 490                 if (ka->sa.sa_flags & SA_SIGINFO)
 491                         idx += 3;
 492
 493                 retcode = AARCH32_VECTORS_BASE +
 494                           AARCH32_KERN_SIGRET_CODE_OFFSET +
 495                           (idx << 2) + thumb;
 496         }
 497
 498         regs->regs[0]   = usig;
 499         regs->compat_sp = ptr_to_compat(frame);
 500         regs->compat_lr = retcode;
 501         regs->pc        = handler;
 502         regs->pstate    = spsr;
 503 }
 504
 505 static int compat_setup_sigframe(struct compat_sigframe __user *sf,
 506                                  struct pt_regs *regs, sigset_t *set)
 507 {
 508         struct compat_aux_sigframe __user *aux;
 509         int err = 0;
 510
 511         __put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
 512         __put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
 513         __put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
 514         __put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
 515         __put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
 516         __put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
 517         __put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
 518         __put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
 519         __put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
 520         __put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
 521         __put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
 522         __put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
 523         __put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
 524         __put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
 525         __put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
 526         __put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
 527         __put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
 528
 529         __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
 530         __put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
 531         __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
 532         __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
 533
 534         err |= put_sigset_t(&sf->uc.uc_sigmask, set);
 535
 536         aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
 537
 538         if (err == 0)
 539                 err |= compat_preserve_vfp_context(&aux->vfp);
 540         __put_user_error(0, &aux->end_magic, err);
 541
 542         return err;
 543 }
 544
 545 /*
 546  * 32-bit signal handling routines called from signal.c
 547  */
 548 int compat_setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
 549                           sigset_t *set, struct pt_regs *regs)
 550 {
 551         struct compat_rt_sigframe __user *frame;
 552         int err = 0;
 553
 554         frame = compat_get_sigframe(ka, regs, sizeof(*frame));
 555
 556         if (!frame)
 557                 return 1;
 558
 559         err |= copy_siginfo_to_user32(&frame->info, info);
 560
 561         __put_user_error(0, &frame->sig.uc.uc_flags, err);
 562         __put_user_error(0, &frame->sig.uc.uc_link, err);
 563
 564         err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
 565
 566         err |= compat_setup_sigframe(&frame->sig, regs, set);
 567
 568         if (err == 0) {
 569                 compat_setup_return(regs, ka, frame->sig.retcode, frame, usig);
 570                 regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
 571                 regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
 572         }
 573
 574         return err;
 575 }
 576
 577 int compat_setup_frame(int usig, struct k_sigaction *ka, sigset_t *set,
 578                        struct pt_regs *regs)
 579 {
 580         struct compat_sigframe __user *frame;
 581         int err = 0;
 582
 583         frame = compat_get_sigframe(ka, regs, sizeof(*frame));
 584
 585         if (!frame)
 586                 return 1;
 587
 588         __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
 589
 590         err |= compat_setup_sigframe(frame, regs, set);
 591         if (err == 0)
 592                 compat_setup_return(regs, ka, frame->retcode, frame, usig);
 593
 594         return err;
 595 }
 596
 597 void compat_setup_restart_syscall(struct pt_regs *regs)
 598 {
 599        regs->regs[7] = __NR_compat_restart_syscall;
 600 }