sysdeps/unix/sysv/linux/mmap.c

   1 /* mmap - map files or devices into memory.  Linux version.
   2    Copyright (C) 2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <sys/mman.h>
  22 #include <sysdep.h>
  23 #include <stdint.h>
  24 #include <mmap_internal.h>
  25
  26 #ifndef __OFF_T_MATCHES_OFF64_T
  27
  28 /* An architecture may override this.  */
  29 # ifndef MMAP_ADJUST_OFFSET
  30 #  define MMAP_ADJUST_OFFSET(offset) offset
  31 # endif
  32
  33 void *
  34 __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset)
  35 {
  36   MMAP_CHECK_PAGE_UNIT ();
  37
  38   if (offset & MMAP_OFF_LOW_MASK)
  39     return (__ptr_t) INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL);
  40
  41 #ifdef __NR_mmap2
  42   return (void *) MMAP_CALL (mmap2, addr, len, prot, flags, fd,
  43                              offset / (uint32_t) MMAP2_PAGE_UNIT);
  44 #else
  45   return (void *) MMAP_CALL (mmap, addr, len, prot, flags, fd,
  46                              MMAP_ADJUST_OFFSET (offset));
  47 #endif
  48 }
  49 weak_alias (__mmap, mmap)
  50
  51 #endif /* __OFF_T_MATCHES_OFF64_T  */