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
       This  is  probably  not  the system call that you are interested in; instead, see mmap(2),
       which describes the glibc wrapper function that invokes this system call.

       The mmap2() system call provides the same interface 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 user space.

       EINVAL (Various platforms where the page size is not 4096 bytes.)  offset * 4096 is not  a
              multiple of the system page size.

       mmap2() can also return any of the errors described in mmap(2).

VERSIONS
       mmap2() is available since Linux 2.3.31.

CONFORMING TO
       This system call is Linux-specific.

NOTES
       On  architectures  where  this  system  call is present, the glibc mmap() wrapper function
       invokes this system call rather than the mmap(2) system call.

       This system call does not exist on x86-64.

       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 3.74 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2014-02-25                                   MMAP2(2)