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       This  is  probably  not  the  system  call  that you are interested in;
16       instead, see mmap(2), which describes the glibc wrapper  function  that
17       invokes this system call.
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19       The  mmap2() system call provides the same interface as mmap(2), except
20       that the final argument specifies the offset into the file in 4096-byte
21       units (instead of bytes, as is done by mmap(2)).  This enables applica‐
22       tions that use a 32-bit off_t to map large files (up to 2^44 bytes).
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RETURN VALUE

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

29       EFAULT Problem with getting the data from user space.
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31       EINVAL (Various platforms where the page size is not 4096 bytes.)  off‐
32              set * 4096 is not a multiple of the system page size.
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34       mmap2() can also return any of the errors described in mmap(2).
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VERSIONS

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

40       This system call is Linux-specific.
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NOTES

43       On architectures where this system call is present,  the  glibc  mmap()
44       wrapper  function invokes this system call rather than the mmap(2) sys‐
45       tem call.
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47       This system call does not exist on x86-64.
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49       On ia64, the unit for offset is actually the system page  size,  rather
50       than 4096 bytes.
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SEE ALSO

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

56       This  page  is  part of release 5.02 of the Linux man-pages project.  A
57       description of the project, information about reporting bugs,  and  the
58       latest     version     of     this    page,    can    be    found    at
59       https://www.kernel.org/doc/man-pages/.
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63Linux                             2017-09-15                          MMAP2(2)
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