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);
void *mmap_pgoff(void *addr, size_t length, int prot,
int flags, int fd, unsigned long pgoffset);
DESCRIPTION
The mmap2() and mmap_pgoff() system calls operate 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).
The system call mmap2() is available on non-x86 platforms whereas
mmap_pgoff() is available on x86 64 bit platforms.
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.) off‐
set * 4096 is not a multiple of the system page size.
mmap2() can return any of the same errors as mmap(2).
VERSIONSmmap2() 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 ALSOgetpagesize(2), mmap(2), mremap(2), msync(2), shm_open(3)COLOPHON
This page is part of release 3.22 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/.
Linux 2008-04-22 MMAP2(2)
