MMAP2(2) - man page online | system calls

Map files or devices into memory.

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);
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 appropriately.
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.
CONFORMING TO 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)
COLOPHON This page is part of release 4.04 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 2014-02-25 MMAP2(2)
This manual Reference Other manuals
mmap2(2) referred by mmap(2) | remap_file_pages(2) | syscalls(2)
refer to getpagesize(2) | mmap(2) | mremap(2) | msync(2) | shm_open(3)