MMAP2
Section: Linux Programmer's Manual (2)
Updated: 2008-04-22
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 3.27 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
This document was created by
man2html,
using the manual pages.
Time: 07:34:56 GMT, March 26, 2013