System Calls Manual
NAME mremap — re-map a virtual memory address
LIBRARY Standard C Library (libc, -lc)
SYNOPSIS #include <sys/mman.h>
mremap(void *oldp, size_t oldsize, void *newp, size_t newsize, int flags);
() function resizes the mapped range (see mmap(2)
) starting at oldp
and having size oldsize
. The following arguments can be OR
'ed together in the flags
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.
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.
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.
HISTORY The mremap() system call appeared in NetBSD 5.0. It was based on the code that supports mremap() compatibility for Linux binaries.