NAME
mremap
- re-map a virtual memory address
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
void
*
mremap(
void *oldp
, size_t oldsize
, void *newp
, size_t newsize
, int flags
)
DESCRIPTION
The
mremap(
)
function resizes the mapped range (see
mmap(2))
starting at
oldp
and having size
oldsize
to
newsize.
The following arguments can be
OR
Ap
ed
together in the
flags
argument:
MAP_ALIGNED
(n)-
The allocation should be aligned to the given boundary, i.e. ensure
that the lowest
n
bits of the address are zero.
The parameter
n
should be the base 2 logarithm of the desired alignment (e.g., to
request alignment to 16K, use 14 as the value for n).
The alignment must be equal to or greater than the platform's page
size as returned by
sysconf(3)
with the
_SC_PAGESIZE
request.
MAP_FIXED
-
newp
is tried and
mremap(
)
fails if that address can't be used as new base address for the range.
Otherwise,
oldp
and
newp
are used as hints for the position, factoring in the given alignment.
RETURN VALUES
mremap(
)
returns the new address or
MAP_FAILED
,
if the remap failed.
HISTORY
The
mremap(
)
system call appeared in
NetBSD5.0.
It was based on the code that supports
mremap(
)
compatibility for Linux binaries.
COMPATIBILITY
The semantics of
mremap(
)
differ from the one provided by glibc on Linux in that the
newp
argument was added and a different set of
flags
are implemented.
SEE ALSO
mmap(2),
munmap(2)