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/*
* Copyright (c) 2012 Chris Johns (chrisj@rtems.org)
* Copyright (c) 2017 Gedare Bloom (gedare@rtems.org)
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <rtems/posix/mmanimpl.h>
#include <rtems/posix/shmimpl.h>
int munmap(void *addr, size_t len)
{
mmap_mapping *mapping;
rtems_chain_node *node;
/*
* Clear errno.
*/
errno = 0;
/*
* Length cannot be 0.
*/
if ( len == 0 ) {
errno = EINVAL;
return -1;
}
/* Check for illegal addresses. Watch out for address wrap. */
if (addr + len < addr) {
errno = EINVAL;
return -1;
}
mmap_mappings_lock_obtain();
node = rtems_chain_first (&mmap_mappings);
while ( !rtems_chain_is_tail( &mmap_mappings, node )) {
mapping = (mmap_mapping*) node;
if ( ( addr >= mapping->addr ) &&
( addr < ( mapping->addr + mapping->len )) ) {
rtems_chain_extract_unprotected( node );
/* FIXME: generally need a way to clean-up the backing object, but
* currently it only matters for MAP_SHARED shm objects. */
if ( mapping->shm != NULL ) {
POSIX_Shm_Attempt_delete(mapping->shm);
}
/* only free the mapping address for non-fixed mapping */
if (( mapping->flags & MAP_FIXED ) != MAP_FIXED ) {
/* only free the mapping address for non-shared mapping, because we
* re-use the mapping address across all of the shared mappings, and
* it is memory managed independently... */
if (( mapping->flags & MAP_SHARED ) != MAP_SHARED ) {
free( mapping->addr );
}
}
free( mapping );
break;
}
node = rtems_chain_next( node );
}
mmap_mappings_lock_release( );
return 0;
}
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