misc/mmap64.c

   1 /* Copyright (C) 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <sys/mman.h>
  21 #include <sys/types.h>
  22
  23 /* Map addresses starting near ADDR and extending for LEN bytes.  From
  24    OFFSET into the file FD describes according to PROT and FLAGS.  If ADDR
  25    is nonzero, it is the desired mapping address.  If the MAP_FIXED bit is
  26    set in FLAGS, the mapping will be at ADDR exactly (which must be
  27    page-aligned); otherwise the system chooses a convenient nearby address.
  28    The return value is the actual mapping address chosen or MAP_FAILED
  29    for errors (in which case `errno' is set).  A successful `mmap' call
  30    deallocates any previous mapping for the affected region.  */
  31
  32 __ptr_t
  33 __mmap64 (__ptr_t addr, size_t len, int prot, int flags, int fd,
  34           __off64_t offset)
  35 {
  36   off_t small_offset = (off_t) offset;
  37
  38   if (small_offset != offset)
  39     {
  40       /* We cannot do this since the offset is too large.  */
  41       __set_errno (EOVERFLOW);
  42       return MAP_FAILED;
  43     }
  44
  45   return __mmap (addr, len, prot, flags, fd, small_offset);
  46 }
  47
  48 weak_alias (__mmap64, mmap64)