mmap2 - map files or devices into memory
void *mmap2(void *addr, size_t length, int prot,
int flags, int fd, off_t pgoffset);
This is probably not the system call you are interested; instead, see
, which describes the glibc wrapper function that invokes this
() 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
applications that use a 32-bit off_t
to map large files (up to 2^44
On success, mmap2
() returns a pointer to the mapped area. On error -1 is
returned and errno
is set appropriately.
- Problem with getting the data from user space.
- (Various platforms where the page size is not 4096 bytes.)
offset * 4096 is not a multiple of the system page size.
() can also return any of the errors described in mmap(2)
() is available since Linux 2.3.31.
This system call is Linux-specific.
Nowadays, the glibc mmap
() wrapper function invokes this system call
rather than the mmap(2)
On ia64, the unit for offset
is actually the system page size, rather
than 4096 bytes.
This page is part of release 3.44 of the Linux man-pages
description of the project, and information about reporting bugs, can be found