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


     mmap2 - map files or devices into memory


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


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


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


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


     mmap2() is available since Linux 2.3.31.


     This system call is Linux-specific.


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


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


     This  page  is  part of release 4.16 of the Linux man-pages project.  A
     description of the project, information about reporting bugs,  and  the
     latest     version     of     this    page,    can    be    found    at

Linux 2017-09-15 MMAP2(2)

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