NAME

       mmap2 - map files or devices into memory

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <sys/mman.h>    /* Definition of MAP_* and PROT_* constants */
       #include <sys/syscall.h> /* Definition of SYS_* constants */
       #include <unistd.h>

       void *syscall(SYS_mmap2, unsigned long addr, unsigned long length,
                     unsigned long prot, unsigned long flags,
                     unsigned long fd, unsigned long 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 to indicate the error.

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.

STANDARDS

       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)