mmap2(2)

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 you are interested; instead, see
16       mmap(2), which describes the glibc wrapper function that  invokes  this
17       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       Nowadays, the glibc mmap() wrapper function invokes  this  system  call
44       rather than the mmap(2) system call.
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46       On  ia64,  the unit for offset is actually the system page size, rather
47       than 4096 bytes.
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COLOPHON

53       This page is part of release 3.53 of the Linux  man-pages  project.   A
54       description  of  the project, and information about reporting bugs, can
55       be found at http://www.kernel.org/doc/man-pages/.
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59Linux                             2012-04-16                          MMAP2(2)