mmap2(2) - f38

1mmap2(2)                      System Calls Manual                     mmap2(2)
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NAME

6       mmap2 - map files or devices into memory
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <sys/mman.h>    /* Definition of MAP_* and PROT_* constants */
13       #include <sys/syscall.h> /* Definition of SYS_* constants */
14       #include <unistd.h>
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16       void *syscall(SYS_mmap2, unsigned long addr, unsigned long length,
17                     unsigned long prot, unsigned long flags,
18                     unsigned long fd, unsigned long pgoffset);
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DESCRIPTION

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

31       On success, mmap2() returns a pointer to the mapped area.  On error, -1
32       is returned and errno is set to indicate the error.
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ERRORS

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

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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STANDARDS

53       Linux.
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HISTORY

56       Linux 2.3.31.
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