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glibc  2.9
mmap64.c
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00001 /* Copyright (C) 1997 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <errno.h>
00020 #include <sys/mman.h>
00021 #include <sys/types.h>
00022 
00023 /* Map addresses starting near ADDR and extending for LEN bytes.  From
00024    OFFSET into the file FD describes according to PROT and FLAGS.  If ADDR
00025    is nonzero, it is the desired mapping address.  If the MAP_FIXED bit is
00026    set in FLAGS, the mapping will be at ADDR exactly (which must be
00027    page-aligned); otherwise the system chooses a convenient nearby address.
00028    The return value is the actual mapping address chosen or MAP_FAILED
00029    for errors (in which case `errno' is set).  A successful `mmap' call
00030    deallocates any previous mapping for the affected region.  */
00031 
00032 __ptr_t
00033 __mmap64 (__ptr_t addr, size_t len, int prot, int flags, int fd,
00034          __off64_t offset)
00035 {
00036   off_t small_offset = (off_t) offset;
00037 
00038   if (small_offset != offset)
00039     {
00040       /* We cannot do this since the offset is too large.  */
00041       __set_errno (EOVERFLOW);
00042       return MAP_FAILED;
00043     }
00044 
00045   return __mmap (addr, len, prot, flags, fd, small_offset);
00046 }
00047 
00048 weak_alias (__mmap64, mmap64)