arch/s390/kernel/compat_linux.c

   1 /*
   2  *  arch/s390x/kernel/linux32.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Gerhard Tonn (ton@de.ibm.com)
   8  *               Thomas Spatzier (tspat@de.ibm.com)
   9  *
  10  *  Conversion between 31bit and 64bit native syscalls.
  11  *
  12  * Heavily inspired by the 32-bit Sparc compat code which is
  13  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
  14  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
  15  *
  16  */
  17
  18
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/file.h>
  24 #include <linux/signal.h>
  25 #include <linux/resource.h>
  26 #include <linux/times.h>
  27 #include <linux/smp.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/sem.h>
  30 #include <linux/msg.h>
  31 #include <linux/shm.h>
  32 #include <linux/uio.h>
  33 #include <linux/quota.h>
  34 #include <linux/module.h>
  35 #include <linux/poll.h>
  36 #include <linux/personality.h>
  37 #include <linux/stat.h>
  38 #include <linux/filter.h>
  39 #include <linux/highmem.h>
  40 #include <linux/highuid.h>
  41 #include <linux/mman.h>
  42 #include <linux/ipv6.h>
  43 #include <linux/in.h>
  44 #include <linux/icmpv6.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/sysctl.h>
  47 #include <linux/binfmts.h>
  48 #include <linux/capability.h>
  49 #include <linux/compat.h>
  50 #include <linux/vfs.h>
  51 #include <linux/ptrace.h>
  52 #include <linux/fadvise.h>
  53 #include <linux/ipc.h>
  54 #include <linux/slab.h>
  55
  56 #include <asm/types.h>
  57 #include <asm/uaccess.h>
  58
  59 #include <net/scm.h>
  60 #include <net/sock.h>
  61
  62 #include "compat_linux.h"
  63
  64 long psw_user32_bits    = (PSW_BASE32_BITS | PSW_MASK_DAT | PSW_ASC_HOME |
  65                            PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK |
  66                            PSW_MASK_PSTATE | PSW_DEFAULT_KEY);
  67 long psw32_user_bits    = (PSW32_BASE_BITS | PSW32_MASK_DAT | PSW32_ASC_HOME |
  68                            PSW32_MASK_IO | PSW32_MASK_EXT | PSW32_MASK_MCHECK |
  69                            PSW32_MASK_PSTATE);
  70
  71 /* For this source file, we want overflow handling. */
  72
  73 #undef high2lowuid
  74 #undef high2lowgid
  75 #undef low2highuid
  76 #undef low2highgid
  77 #undef SET_UID16
  78 #undef SET_GID16
  79 #undef NEW_TO_OLD_UID
  80 #undef NEW_TO_OLD_GID
  81 #undef SET_OLDSTAT_UID
  82 #undef SET_OLDSTAT_GID
  83 #undef SET_STAT_UID
  84 #undef SET_STAT_GID
  85
  86 #define high2lowuid(uid) ((uid) > 65535) ? (u16)overflowuid : (u16)(uid)
  87 #define high2lowgid(gid) ((gid) > 65535) ? (u16)overflowgid : (u16)(gid)
  88 #define low2highuid(uid) ((uid) == (u16)-1) ? (uid_t)-1 : (uid_t)(uid)
  89 #define low2highgid(gid) ((gid) == (u16)-1) ? (gid_t)-1 : (gid_t)(gid)
  90 #define SET_UID16(var, uid)     var = high2lowuid(uid)
  91 #define SET_GID16(var, gid)     var = high2lowgid(gid)
  92 #define NEW_TO_OLD_UID(uid)     high2lowuid(uid)
  93 #define NEW_TO_OLD_GID(gid)     high2lowgid(gid)
  94 #define SET_OLDSTAT_UID(stat, uid)      (stat).st_uid = high2lowuid(uid)
  95 #define SET_OLDSTAT_GID(stat, gid)      (stat).st_gid = high2lowgid(gid)
  96 #define SET_STAT_UID(stat, uid)         (stat).st_uid = high2lowuid(uid)
  97 #define SET_STAT_GID(stat, gid)         (stat).st_gid = high2lowgid(gid)
  98
  99 asmlinkage long sys32_chown16(const char __user * filename, u16 user, u16 group)
 100 {
 101         return sys_chown(filename, low2highuid(user), low2highgid(group));
 102 }
 103
 104 asmlinkage long sys32_lchown16(const char __user * filename, u16 user, u16 group)
 105 {
 106         return sys_lchown(filename, low2highuid(user), low2highgid(group));
 107 }
 108
 109 asmlinkage long sys32_fchown16(unsigned int fd, u16 user, u16 group)
 110 {
 111         return sys_fchown(fd, low2highuid(user), low2highgid(group));
 112 }
 113
 114 asmlinkage long sys32_setregid16(u16 rgid, u16 egid)
 115 {
 116         return sys_setregid(low2highgid(rgid), low2highgid(egid));
 117 }
 118
 119 asmlinkage long sys32_setgid16(u16 gid)
 120 {
 121         return sys_setgid((gid_t)gid);
 122 }
 123
 124 asmlinkage long sys32_setreuid16(u16 ruid, u16 euid)
 125 {
 126         return sys_setreuid(low2highuid(ruid), low2highuid(euid));
 127 }
 128
 129 asmlinkage long sys32_setuid16(u16 uid)
 130 {
 131         return sys_setuid((uid_t)uid);
 132 }
 133
 134 asmlinkage long sys32_setresuid16(u16 ruid, u16 euid, u16 suid)
 135 {
 136         return sys_setresuid(low2highuid(ruid), low2highuid(euid),
 137                 low2highuid(suid));
 138 }
 139
 140 asmlinkage long sys32_getresuid16(u16 __user *ruid, u16 __user *euid, u16 __user *suid)
 141 {
 142         int retval;
 143
 144         if (!(retval = put_user(high2lowuid(current->cred->uid), ruid)) &&
 145             !(retval = put_user(high2lowuid(current->cred->euid), euid)))
 146                 retval = put_user(high2lowuid(current->cred->suid), suid);
 147
 148         return retval;
 149 }
 150
 151 asmlinkage long sys32_setresgid16(u16 rgid, u16 egid, u16 sgid)
 152 {
 153         return sys_setresgid(low2highgid(rgid), low2highgid(egid),
 154                 low2highgid(sgid));
 155 }
 156
 157 asmlinkage long sys32_getresgid16(u16 __user *rgid, u16 __user *egid, u16 __user *sgid)
 158 {
 159         int retval;
 160
 161         if (!(retval = put_user(high2lowgid(current->cred->gid), rgid)) &&
 162             !(retval = put_user(high2lowgid(current->cred->egid), egid)))
 163                 retval = put_user(high2lowgid(current->cred->sgid), sgid);
 164
 165         return retval;
 166 }
 167
 168 asmlinkage long sys32_setfsuid16(u16 uid)
 169 {
 170         return sys_setfsuid((uid_t)uid);
 171 }
 172
 173 asmlinkage long sys32_setfsgid16(u16 gid)
 174 {
 175         return sys_setfsgid((gid_t)gid);
 176 }
 177
 178 static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
 179 {
 180         int i;
 181         u16 group;
 182
 183         for (i = 0; i < group_info->ngroups; i++) {
 184                 group = (u16)GROUP_AT(group_info, i);
 185                 if (put_user(group, grouplist+i))
 186                         return -EFAULT;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
 193 {
 194         int i;
 195         u16 group;
 196
 197         for (i = 0; i < group_info->ngroups; i++) {
 198                 if (get_user(group, grouplist+i))
 199                         return  -EFAULT;
 200                 GROUP_AT(group_info, i) = (gid_t)group;
 201         }
 202
 203         return 0;
 204 }
 205
 206 asmlinkage long sys32_getgroups16(int gidsetsize, u16 __user *grouplist)
 207 {
 208         int i;
 209
 210         if (gidsetsize < 0)
 211                 return -EINVAL;
 212
 213         get_group_info(current->cred->group_info);
 214         i = current->cred->group_info->ngroups;
 215         if (gidsetsize) {
 216                 if (i > gidsetsize) {
 217                         i = -EINVAL;
 218                         goto out;
 219                 }
 220                 if (groups16_to_user(grouplist, current->cred->group_info)) {
 221                         i = -EFAULT;
 222                         goto out;
 223                 }
 224         }
 225 out:
 226         put_group_info(current->cred->group_info);
 227         return i;
 228 }
 229
 230 asmlinkage long sys32_setgroups16(int gidsetsize, u16 __user *grouplist)
 231 {
 232         struct group_info *group_info;
 233         int retval;
 234
 235         if (!capable(CAP_SETGID))
 236                 return -EPERM;
 237         if ((unsigned)gidsetsize > NGROUPS_MAX)
 238                 return -EINVAL;
 239
 240         group_info = groups_alloc(gidsetsize);
 241         if (!group_info)
 242                 return -ENOMEM;
 243         retval = groups16_from_user(group_info, grouplist);
 244         if (retval) {
 245                 put_group_info(group_info);
 246                 return retval;
 247         }
 248
 249         retval = set_current_groups(group_info);
 250         put_group_info(group_info);
 251
 252         return retval;
 253 }
 254
 255 asmlinkage long sys32_getuid16(void)
 256 {
 257         return high2lowuid(current->cred->uid);
 258 }
 259
 260 asmlinkage long sys32_geteuid16(void)
 261 {
 262         return high2lowuid(current->cred->euid);
 263 }
 264
 265 asmlinkage long sys32_getgid16(void)
 266 {
 267         return high2lowgid(current->cred->gid);
 268 }
 269
 270 asmlinkage long sys32_getegid16(void)
 271 {
 272         return high2lowgid(current->cred->egid);
 273 }
 274
 275 /*
 276  * sys32_ipc() is the de-multiplexer for the SysV IPC calls in 32bit emulation.
 277  *
 278  * This is really horribly ugly.
 279  */
 280 #ifdef CONFIG_SYSVIPC
 281 asmlinkage long sys32_ipc(u32 call, int first, int second, int third, u32 ptr)
 282 {
 283         if (call >> 16)         /* hack for backward compatibility */
 284                 return -EINVAL;
 285
 286         call &= 0xffff;
 287
 288         switch (call) {
 289         case SEMTIMEDOP:
 290                 return compat_sys_semtimedop(first, compat_ptr(ptr),
 291                                              second, compat_ptr(third));
 292         case SEMOP:
 293                 /* struct sembuf is the same on 32 and 64bit :)) */
 294                 return sys_semtimedop(first, compat_ptr(ptr),
 295                                       second, NULL);
 296         case SEMGET:
 297                 return sys_semget(first, second, third);
 298         case SEMCTL:
 299                 return compat_sys_semctl(first, second, third,
 300                                          compat_ptr(ptr));
 301         case MSGSND:
 302                 return compat_sys_msgsnd(first, second, third,
 303                                          compat_ptr(ptr));
 304         case MSGRCV:
 305                 return compat_sys_msgrcv(first, second, 0, third,
 306                                          0, compat_ptr(ptr));
 307         case MSGGET:
 308                 return sys_msgget((key_t) first, second);
 309         case MSGCTL:
 310                 return compat_sys_msgctl(first, second, compat_ptr(ptr));
 311         case SHMAT:
 312                 return compat_sys_shmat(first, second, third,
 313                                         0, compat_ptr(ptr));
 314         case SHMDT:
 315                 return sys_shmdt(compat_ptr(ptr));
 316         case SHMGET:
 317                 return sys_shmget(first, (unsigned)second, third);
 318         case SHMCTL:
 319                 return compat_sys_shmctl(first, second, compat_ptr(ptr));
 320         }
 321
 322         return -ENOSYS;
 323 }
 324 #endif
 325
 326 asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, unsigned long low)
 327 {
 328         if ((int)high < 0)
 329                 return -EINVAL;
 330         else
 331                 return sys_truncate(path, (high << 32) | low);
 332 }
 333
 334 asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
 335 {
 336         if ((int)high < 0)
 337                 return -EINVAL;
 338         else
 339                 return sys_ftruncate(fd, (high << 32) | low);
 340 }
 341
 342 asmlinkage long sys32_sched_rr_get_interval(compat_pid_t pid,
 343                                 struct compat_timespec __user *interval)
 344 {
 345         struct timespec t;
 346         int ret;
 347         mm_segment_t old_fs = get_fs ();
 348
 349         set_fs (KERNEL_DS);
 350         ret = sys_sched_rr_get_interval(pid,
 351                                         (struct timespec __force __user *) &t);
 352         set_fs (old_fs);
 353         if (put_compat_timespec(&t, interval))
 354                 return -EFAULT;
 355         return ret;
 356 }
 357
 358 asmlinkage long sys32_rt_sigprocmask(int how, compat_sigset_t __user *set,
 359                         compat_sigset_t __user *oset, size_t sigsetsize)
 360 {
 361         sigset_t s;
 362         compat_sigset_t s32;
 363         int ret;
 364         mm_segment_t old_fs = get_fs();
 365
 366         if (set) {
 367                 if (copy_from_user (&s32, set, sizeof(compat_sigset_t)))
 368                         return -EFAULT;
 369                 switch (_NSIG_WORDS) {
 370                 case 4: s.sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32);
 371                 case 3: s.sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32);
 372                 case 2: s.sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32);
 373                 case 1: s.sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
 374                 }
 375         }
 376         set_fs (KERNEL_DS);
 377         ret = sys_rt_sigprocmask(how,
 378                                  set ? (sigset_t __force __user *) &s : NULL,
 379                                  oset ? (sigset_t __force __user *) &s : NULL,
 380                                  sigsetsize);
 381         set_fs (old_fs);
 382         if (ret) return ret;
 383         if (oset) {
 384                 switch (_NSIG_WORDS) {
 385                 case 4: s32.sig[7] = (s.sig[3] >> 32); s32.sig[6] = s.sig[3];
 386                 case 3: s32.sig[5] = (s.sig[2] >> 32); s32.sig[4] = s.sig[2];
 387                 case 2: s32.sig[3] = (s.sig[1] >> 32); s32.sig[2] = s.sig[1];
 388                 case 1: s32.sig[1] = (s.sig[0] >> 32); s32.sig[0] = s.sig[0];
 389                 }
 390                 if (copy_to_user (oset, &s32, sizeof(compat_sigset_t)))
 391                         return -EFAULT;
 392         }
 393         return 0;
 394 }
 395
 396 asmlinkage long sys32_rt_sigpending(compat_sigset_t __user *set,
 397                                 size_t sigsetsize)
 398 {
 399         sigset_t s;
 400         compat_sigset_t s32;
 401         int ret;
 402         mm_segment_t old_fs = get_fs();
 403
 404         set_fs (KERNEL_DS);
 405         ret = sys_rt_sigpending((sigset_t __force __user *) &s, sigsetsize);
 406         set_fs (old_fs);
 407         if (!ret) {
 408                 switch (_NSIG_WORDS) {
 409                 case 4: s32.sig[7] = (s.sig[3] >> 32); s32.sig[6] = s.sig[3];
 410                 case 3: s32.sig[5] = (s.sig[2] >> 32); s32.sig[4] = s.sig[2];
 411                 case 2: s32.sig[3] = (s.sig[1] >> 32); s32.sig[2] = s.sig[1];
 412                 case 1: s32.sig[1] = (s.sig[0] >> 32); s32.sig[0] = s.sig[0];
 413                 }
 414                 if (copy_to_user (set, &s32, sizeof(compat_sigset_t)))
 415                         return -EFAULT;
 416         }
 417         return ret;
 418 }
 419
 420 asmlinkage long
 421 sys32_rt_sigqueueinfo(int pid, int sig, compat_siginfo_t __user *uinfo)
 422 {
 423         siginfo_t info;
 424         int ret;
 425         mm_segment_t old_fs = get_fs();
 426
 427         if (copy_siginfo_from_user32(&info, uinfo))
 428                 return -EFAULT;
 429         set_fs (KERNEL_DS);
 430         ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *) &info);
 431         set_fs (old_fs);
 432         return ret;
 433 }
 434
 435 /*
 436  * sys32_execve() executes a new program after the asm stub has set
 437  * things up for us.  This should basically do what I want it to.
 438  */
 439 asmlinkage long sys32_execve(char __user *name, compat_uptr_t __user *argv,
 440                              compat_uptr_t __user *envp)
 441 {
 442         struct pt_regs *regs = task_pt_regs(current);
 443         char *filename;
 444         long rc;
 445
 446         filename = getname(name);
 447         rc = PTR_ERR(filename);
 448         if (IS_ERR(filename))
 449                 return rc;
 450         rc = compat_do_execve(filename, argv, envp, regs);
 451         if (rc)
 452                 goto out;
 453         current->thread.fp_regs.fpc=0;
 454         asm volatile("sfpc %0,0" : : "d" (0));
 455         rc = regs->gprs[2];
 456 out:
 457         putname(filename);
 458         return rc;
 459 }
 460
 461 asmlinkage long sys32_pread64(unsigned int fd, char __user *ubuf,
 462                                 size_t count, u32 poshi, u32 poslo)
 463 {
 464         if ((compat_ssize_t) count < 0)
 465                 return -EINVAL;
 466         return sys_pread64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
 467 }
 468
 469 asmlinkage long sys32_pwrite64(unsigned int fd, const char __user *ubuf,
 470                                 size_t count, u32 poshi, u32 poslo)
 471 {
 472         if ((compat_ssize_t) count < 0)
 473                 return -EINVAL;
 474         return sys_pwrite64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
 475 }
 476
 477 asmlinkage compat_ssize_t sys32_readahead(int fd, u32 offhi, u32 offlo, s32 count)
 478 {
 479         return sys_readahead(fd, ((loff_t)AA(offhi) << 32) | AA(offlo), count);
 480 }
 481
 482 asmlinkage long sys32_sendfile(int out_fd, int in_fd, compat_off_t __user *offset, size_t count)
 483 {
 484         mm_segment_t old_fs = get_fs();
 485         int ret;
 486         off_t of;
 487
 488         if (offset && get_user(of, offset))
 489                 return -EFAULT;
 490
 491         set_fs(KERNEL_DS);
 492         ret = sys_sendfile(out_fd, in_fd,
 493                            offset ? (off_t __force __user *) &of : NULL, count);
 494         set_fs(old_fs);
 495
 496         if (offset && put_user(of, offset))
 497                 return -EFAULT;
 498
 499         return ret;
 500 }
 501
 502 asmlinkage long sys32_sendfile64(int out_fd, int in_fd,
 503                                 compat_loff_t __user *offset, s32 count)
 504 {
 505         mm_segment_t old_fs = get_fs();
 506         int ret;
 507         loff_t lof;
 508
 509         if (offset && get_user(lof, offset))
 510                 return -EFAULT;
 511
 512         set_fs(KERNEL_DS);
 513         ret = sys_sendfile64(out_fd, in_fd,
 514                              offset ? (loff_t __force __user *) &lof : NULL,
 515                              count);
 516         set_fs(old_fs);
 517
 518         if (offset && put_user(lof, offset))
 519                 return -EFAULT;
 520
 521         return ret;
 522 }
 523
 524 struct stat64_emu31 {
 525         unsigned long long  st_dev;
 526         unsigned int    __pad1;
 527 #define STAT64_HAS_BROKEN_ST_INO        1
 528         u32             __st_ino;
 529         unsigned int    st_mode;
 530         unsigned int    st_nlink;
 531         u32             st_uid;
 532         u32             st_gid;
 533         unsigned long long  st_rdev;
 534         unsigned int    __pad3;
 535         long            st_size;
 536         u32             st_blksize;
 537         unsigned char   __pad4[4];
 538         u32             __pad5;     /* future possible st_blocks high bits */
 539         u32             st_blocks;  /* Number 512-byte blocks allocated. */
 540         u32             st_atime;
 541         u32             __pad6;
 542         u32             st_mtime;
 543         u32             __pad7;
 544         u32             st_ctime;
 545         u32             __pad8;     /* will be high 32 bits of ctime someday */
 546         unsigned long   st_ino;
 547 };
 548
 549 static int cp_stat64(struct stat64_emu31 __user *ubuf, struct kstat *stat)
 550 {
 551         struct stat64_emu31 tmp;
 552
 553         memset(&tmp, 0, sizeof(tmp));
 554
 555         tmp.st_dev = huge_encode_dev(stat->dev);
 556         tmp.st_ino = stat->ino;
 557         tmp.__st_ino = (u32)stat->ino;
 558         tmp.st_mode = stat->mode;
 559         tmp.st_nlink = (unsigned int)stat->nlink;
 560         tmp.st_uid = stat->uid;
 561         tmp.st_gid = stat->gid;
 562         tmp.st_rdev = huge_encode_dev(stat->rdev);
 563         tmp.st_size = stat->size;
 564         tmp.st_blksize = (u32)stat->blksize;
 565         tmp.st_blocks = (u32)stat->blocks;
 566         tmp.st_atime = (u32)stat->atime.tv_sec;
 567         tmp.st_mtime = (u32)stat->mtime.tv_sec;
 568         tmp.st_ctime = (u32)stat->ctime.tv_sec;
 569
 570         return copy_to_user(ubuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
 571 }
 572
 573 asmlinkage long sys32_stat64(char __user * filename, struct stat64_emu31 __user * statbuf)
 574 {
 575         struct kstat stat;
 576         int ret = vfs_stat(filename, &stat);
 577         if (!ret)
 578                 ret = cp_stat64(statbuf, &stat);
 579         return ret;
 580 }
 581
 582 asmlinkage long sys32_lstat64(char __user * filename, struct stat64_emu31 __user * statbuf)
 583 {
 584         struct kstat stat;
 585         int ret = vfs_lstat(filename, &stat);
 586         if (!ret)
 587                 ret = cp_stat64(statbuf, &stat);
 588         return ret;
 589 }
 590
 591 asmlinkage long sys32_fstat64(unsigned long fd, struct stat64_emu31 __user * statbuf)
 592 {
 593         struct kstat stat;
 594         int ret = vfs_fstat(fd, &stat);
 595         if (!ret)
 596                 ret = cp_stat64(statbuf, &stat);
 597         return ret;
 598 }
 599
 600 asmlinkage long sys32_fstatat64(unsigned int dfd, char __user *filename,
 601                                 struct stat64_emu31 __user* statbuf, int flag)
 602 {
 603         struct kstat stat;
 604         int error;
 605
 606         error = vfs_fstatat(dfd, filename, &stat, flag);
 607         if (error)
 608                 return error;
 609         return cp_stat64(statbuf, &stat);
 610 }
 611
 612 /*
 613  * Linux/i386 didn't use to be able to handle more than
 614  * 4 system call parameters, so these system calls used a memory
 615  * block for parameter passing..
 616  */
 617
 618 struct mmap_arg_struct_emu31 {
 619         compat_ulong_t addr;
 620         compat_ulong_t len;
 621         compat_ulong_t prot;
 622         compat_ulong_t flags;
 623         compat_ulong_t fd;
 624         compat_ulong_t offset;
 625 };
 626
 627 asmlinkage unsigned long old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
 628 {
 629         struct mmap_arg_struct_emu31 a;
 630
 631         if (copy_from_user(&a, arg, sizeof(a)))
 632                 return -EFAULT;
 633         if (a.offset & ~PAGE_MASK)
 634                 return -EINVAL;
 635         a.addr = (unsigned long) compat_ptr(a.addr);
 636         return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
 637                               a.offset >> PAGE_SHIFT);
 638 }
 639
 640 asmlinkage long sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg)
 641 {
 642         struct mmap_arg_struct_emu31 a;
 643
 644         if (copy_from_user(&a, arg, sizeof(a)))
 645                 return -EFAULT;
 646         a.addr = (unsigned long) compat_ptr(a.addr);
 647         return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 648 }
 649
 650 asmlinkage long sys32_read(unsigned int fd, char __user * buf, size_t count)
 651 {
 652         if ((compat_ssize_t) count < 0)
 653                 return -EINVAL;
 654
 655         return sys_read(fd, buf, count);
 656 }
 657
 658 asmlinkage long sys32_write(unsigned int fd, char __user * buf, size_t count)
 659 {
 660         if ((compat_ssize_t) count < 0)
 661                 return -EINVAL;
 662
 663         return sys_write(fd, buf, count);
 664 }
 665
 666 /*
 667  * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
 668  * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
 669  * because the 31 bit values differ from the 64 bit values.
 670  */
 671
 672 asmlinkage long
 673 sys32_fadvise64(int fd, loff_t offset, size_t len, int advise)
 674 {
 675         if (advise == 4)
 676                 advise = POSIX_FADV_DONTNEED;
 677         else if (advise == 5)
 678                 advise = POSIX_FADV_NOREUSE;
 679         return sys_fadvise64(fd, offset, len, advise);
 680 }
 681
 682 struct fadvise64_64_args {
 683         int fd;
 684         long long offset;
 685         long long len;
 686         int advice;
 687 };
 688
 689 asmlinkage long
 690 sys32_fadvise64_64(struct fadvise64_64_args __user *args)
 691 {
 692         struct fadvise64_64_args a;
 693
 694         if ( copy_from_user(&a, args, sizeof(a)) )
 695                 return -EFAULT;
 696         if (a.advice == 4)
 697                 a.advice = POSIX_FADV_DONTNEED;
 698         else if (a.advice == 5)
 699                 a.advice = POSIX_FADV_NOREUSE;
 700         return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
 701 }