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