* libs/libc/dlfcn/lib_dlclose.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <dlfcn.h>
#include <nuttx/lib/elf.h>
* Private Functions
****************************************************************************/
* Public Functions
****************************************************************************/
* Name: dlclose
*
* Description:
* dlclose() is used to inform the system that the object referenced by a
* handle returned from a previous dlopen() invocation is no longer needed
* by the application.
*
* The use of dlclose() reflects a statement of intent on the part of the
* process, but does not create any requirement upon the implementation,
* such as removal of the code or symbols referenced by handle. Once an
* object has been closed using dlclose() an application should assume
* that its symbols are no longer available to dlsym(). All objects loaded
* automatically as a result of invoking dlopen() on the referenced object
* are also closed.
*
* Although a dlclose() operation is not required to remove structures
* from an address space, neither is an implementation prohibited from
* doing so. The only restriction on such a removal is that no object will
* be removed to which references have been relocated, until or unless all
* such references are removed. For instance, an object that had been
* loaded with a dlopen() operation specifying the RTLD_GLOBAL flag might
* provide a target for dynamic relocations performed in the processing of
* other objects - in such environments, an application may assume that no
* relocation, once made, will be undone or remade unless the object
* requiring the relocation has itself been removed.
*
* Input Parameters:
* handle - The opaque, non-NULL value returned by a previous successful
* call to dlopen().
*
* Returned Value:
* If the referenced object was successfully closed, dlclose() returns 0.
* If the object could not be closed, or if handle does not refer to an
* open object, dlclose() returns a non-zero value. More detailed
* diagnostic information will be available through dlerror().
*
* Reference: OpenGroup.org
*
****************************************************************************/
int dlclose(FAR void *handle)
{
#if defined(CONFIG_BUILD_FLAT) || defined(CONFIG_BUILD_PROTECTED)
* module.
*
* The PROTECTED build is equivalent to the FLAT build EXCEPT that there
* must be two copies of the module logic: One residing in kernel
* space and using the kernel symbol table and one residing in user space
* using the user space symbol table.
*
* dlremove() is essentially a clone of rmmod().
*/
return libelf_remove(handle);
#else
* the .text portion of the module must be (1) build for PIC/PID operation
* and (2) must like in a shared memory region accessible from all
* processes. The .data/.bss portion of the module must be allocated in
* the user space of each process, but must lie at the same virtual address
* so that it can be referenced from the one copy of the text in the shared
* memory region.
*/
return -ENOSYS;
#endif
}