mmap2(2) — Linux manual page


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

NAME         top

       mmap2 - map files or devices into memory

SYNOPSIS         top

       #include <sys/mman.h>

       void *mmap2(void *addr, size_t length, int prot,
                    int flags, int fd, off_t pgoffset);

DESCRIPTION         top

       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         top

       On success, mmap2() returns a pointer to the mapped area.  On error,
       -1 is returned and errno is set appropriately.

ERRORS         top

       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         top

       mmap2() is available since Linux 2.3.31.

CONFORMING TO         top

       This system call is Linux-specific.

NOTES         top

       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         top

       getpagesize(2), mmap(2), mremap(2), msync(2), shm_open(3)

COLOPHON         top

       This page is part of release 5.08 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

Linux                            2017-09-15                         MMAP2(2)

Pages that refer to this page: mmap(2)munmap(2)remap_file_pages(2)syscalls(2)mmap64(3)