MMAP2(2)                                            Linux Programmer's Manual                                           MMAP2(2)



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 3.25 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/.



Linux                                                      2008-04-22                                                   MMAP2(2)