nuttx/sched/module/mod_insmod.c

/****************************************************************************
 * sched/module/mod_insmod.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 <errno.h>

#include <nuttx/module.h>
#include <nuttx/lib/elf.h>

#ifdef CONFIG_MODULE

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: insmod
 *
 * Description:
 *   Verify that the file is an ELF module binary and, if so, load the
 *   module into kernel memory and initialize it for use.
 *
 *   NOTE: libelf_setsymtab() had to have been called in board-specific OS
 *   logic prior to calling this function from application logic (perhaps via
 *   boardctl(BOARDIOC_OS_SYMTAB).  Otherwise, insmod will be unable to
 *   resolve symbols in the OS module.
 *
 * Input Parameters:
 *
 *   filename - Full path to the module binary to be loaded
 *   modname  - The name that can be used to refer to the module after
 *     it has been loaded.
 *
 * Returned Value:
 *   A non-NULL module handle that can be used on subsequent calls to other
 *   module interfaces is returned on success.  If insmod() was unable to
 *   load the module insmod() will return a NULL handle and the errno
 *   variable will be set appropriately.
 *
 ****************************************************************************/

FAR void *insmod(FAR const char *filename, FAR const char *modname)
{
  /* A duplicate name is an error here, where it has always been.
   * libelf_insert() would take a reference instead, which is what
   * dlopen() wants and insmod() does not.
   */

  if (libelf_gethandle(modname) != NULL)
    {
      set_errno(EEXIST);
      return NULL;
    }

  return libelf_insert(filename, modname);
}

#endif /* CONFIG_MODULE */