mmap2(2) - f14

1MMAP2(2)                   Linux Programmer's Manual                  MMAP2(2)
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NAME

6       mmap2 - map files or devices into memory
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SYNOPSIS

9       #include <sys/mman.h>
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11       void *mmap2(void *addr, size_t length, int prot,
12                    int flags, int fd, off_t pgoffset);
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DESCRIPTION

15       The  mmap2()  system  call operates in exactly the same way as mmap(2),
16       except that the final argument specifies the offset into  the  file  in
17       4096-byte  units  (instead  of  bytes,  as  is  done by mmap(2)).  This
18       enables applications that use a 32-bit off_t to map large files (up  to
19       2^44 bytes).
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RETURN VALUE

22       On  success, mmap2() returns a pointer to the mapped area.  On error -1
23       is returned and errno is set appropriately.
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ERRORS

26       EFAULT Problem with getting the data from userspace.
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28       EINVAL (Various platforms where the page size is not 4096 bytes.)  off‐
29              set * 4096 is not a multiple of the system page size.
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31       mmap2() can return any of the same errors as mmap(2).
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VERSIONS

34       mmap2() is available since Linux 2.3.31.
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CONFORMING TO

37       This system call is Linux-specific.
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NOTES

40       Nowadays,  the  glibc  mmap() wrapper function invokes this system call
41       rather than the mmap(2) system call.
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43       On ia64, the unit for offset is actually the system page  size,  rather
44       than 4096 bytes.
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COLOPHON

50       This  page  is  part of release 3.25 of the Linux man-pages project.  A
51       description of the project, and information about reporting  bugs,  can
52       be found at http://www.kernel.org/doc/man-pages/.
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56Linux                             2008-04-22                          MMAP2(2)