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mmap2(2) — Linux manual page

mmap2(2)                   System Calls Manualmmap2(2)

NAME        top

       mmap2 - map files or devices into memory

LIBRARY        top

       Standard C library (libc,-lc)

SYNOPSIS        top

#include <sys/mman.h>/* Definition ofMAP_*andPROT_*constants */#include <sys/syscall.h>/* Definition ofSYS_*constants */#include <unistd.h>void *syscall(SYS_mmap2, unsigned longaddr, unsigned longlength,unsigned longprot, unsigned longflags,unsigned longfd, unsigned longpgoffset);

DESCRIPTION        top

       This is probably not the system call that you are interested in;       instead, seemmap(2), which describes the glibc wrapper function       that invokes this system call.       Themmap2() system call provides the same interface asmmap(2),       except that the final argument specifies the offset into the file       in 4096-byte units (instead of bytes, as is done bymmap(2)).       This enables applications that use a 32-bitoff_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 anderrno is set to indicate the error.

ERRORS        top

EFAULTProblem 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 inmmap(2).

VERSIONS        top

       On architectures where this system call is present, the glibcmmap() wrapper function invokes this system call rather than themmap(2) system call.       This system call does not exist on x86-64.       On ia64, the unit foroffset is actually the system page size,       rather than 4096 bytes.

STANDARDS        top

       Linux.

HISTORY        top

       Linux 2.3.31.

SEE ALSO        top

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

COLOPHON        top

       This page is part of theman-pages (Linux kernel and C library       user-space interface documentation) project.  Information about       the project can be found at        ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report       for this manual page, see       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.       This page was obtained from the tarball man-pages-6.15.tar.gz       fetched from       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on       2025-08-11.  If you discover any rendering problems in this HTML       version of the page, or you believe there is a better or more up-       to-date source for the page, or you have corrections or       improvements to the information in this COLOPHON (which isnot       part of the original manual page), send a mail to       man-pages@man7.orgLinux man-pages 6.15            2025-05-17mmap2(2)

Pages that refer to this page:mmap(2), remap_file_pages(2), syscalls(2)

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