49.8. Remapping a Mapped Region: mremap()

On most UNIX implementations, once a mapping has been created, its location and size can’t be changed. However, Linux provides the (nonportable) mremap() system call, which permits such changes.

#define _GNU_SOURCE
#include <sys/mman.h>

void *mremap(void *old_address, size_t old_size, size_t new_size,
 int flags, ...);