mmap2 — map files or devices into memory
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.
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
a pointer to the mapped area. On error, −1 is returned
errno is set
Problem with getting the data from user space.
(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).
On architectures where this system call is present, the
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.
This page is part of release 4.07 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
Copyright (C) 2002, Michael Kerrisk
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date. The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein. The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Modified 31 Jan 2002, Michael Kerrisk <mtk.manpagesgmail.com>
Added description of mmap2
Modified, 2004-11-25, mtk -- removed stray #endif in prototype