• NAME
  
  mmap2 - map files or devices into memory
• SYNOPSIS
  

  
   #include <sys/mman.h>
  
   void *mmap2(void * addr , size_t  length , int  prot ,
                 int  flags , int  fd , off_t  pgoffset ); 

• DESCRIPTION
  
  The
  mmap2 ()
  system call operates in exactly the same way as
  mmap(2) ,
  except that the final argument specifies the offset into the
  file in 4096-byte units (instead of bytes, as is done by
  mmap(2) ).
  This enables applications that use a 32-bit
  off_t
  to map large files (up to 2^44 bytes).
  
• RETURN VALUE
  
  On success,
  mmap2 ()
  returns a pointer to the mapped area.
  On error -1 is returned and
  errno
  is set appropriately.
  
• ERRORS
  

  EFAULT

  Problem with getting the data from userspace.
  

  EINVAL

  (Various platforms where the page size is not 4096 bytes.)
  offset * 4096
  is not a multiple of the system page size.
  
  
  
  mmap2 ()
  can return any of the same errors as
  mmap(2) .
  

• VERSIONS
  
  mmap2 ()
  is available since Linux 2.3.31.
  
• CONFORMING TO
  
  This system call is Linux-specific.
  
• NOTES
  
  Nowadays, the glibc
  mmap ()
  wrapper function invokes this system call rather than the
  mmap(2)
  system call.
  
  On ia64, the unit for
  offset
  is actually the system page size, rather than 4096 bytes.
  
  
  
  
• SEE ALSO
  
  getpagesize(2) ,
  mmap(2) ,
  mremap(2) ,
  msync(2) ,
  shm_open(3)
  
• COLOPHON
  
  This page is part of release 3.19 of the Linux
  man-pages
  project.
  A description of the project,
  and information about reporting bugs,
  can be found at
  http://www.kernel.org/doc/man-pages/.
  

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