px4_autopilot/nuttx/binfmt/libelf/libelf_addrenv.c

/****************************************************************************
 * binfmt/libelf/libelf_addrenv.c
 *
 *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <errno.h>
#include <debug.h>

#include <nuttx/arch.h>
#include <nuttx/kmalloc.h>

#include "libelf.h"

/****************************************************************************
 * Pre-Processor Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Constant Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

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

/****************************************************************************
 * Name: elf_addrenv_alloc
 *
 * Description:
 *   Allocate memory for the ELF image (elfalloc). If CONFIG_ADDRENV=n,
 *   elfalloc will be allocated using kzalloc().  If CONFIG_ADDRENV-y, then
 *   elfalloc will be allocated using up_addrenv_create().  In either case,
 *   there will be a unique instance of elfalloc (and stack) for each
 *   instance of a process.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *   envsize - The size (in bytes) of the address environment needed for the
 *     ELF image.
 *
 * Returned Value:
 *   Zero (OK) on success; a negated errno value on failure.
 *
 ****************************************************************************/

int elf_addrenv_alloc(FAR struct elf_loadinfo_s *loadinfo, size_t envsize)
{
#ifdef CONFIG_ADDRENV
  FAR void *vaddr;
  int ret;

  /* Create an address environment for the new ELF task */

  ret = up_addrenv_create(envsize, &loadinfo->addrenv);
  if (ret < 0)
    {
      bdbg("ERROR: up_addrenv_create failed: %d\n", ret);
      return ret;
    }

  /* Get the virtual address associated with the start of the address
   * environment.  This is the base address that we will need to use to
   * access the ELF image (but only if the address environment has been
   * selected.
   */

  ret = up_addrenv_vaddr(loadinfo->addrenv, &vaddr);
  if (ret < 0)
    {
      bdbg("ERROR: up_addrenv_vaddr failed: %d\n", ret);
      return ret;
    }

  loadinfo->elfalloc = (uintptr_t)vaddr;
  return OK;
#else
  /* Allocate memory to hold the ELF image */

  loadinfo->elfalloc = (uintptr_t)kzalloc(envsize);
  if (!loadinfo->elfalloc)
    {
      return -ENOMEM;
    }

  return OK;
#endif
}

/****************************************************************************
 * Name: elf_addrenv_free
 *
 * Description:
 *   Release the address environment previously created by
 *   elf_addrenv_create().  This function  is called only under certain error
 *   conditions after the the module has been loaded but not yet started.
 *   After the module has been started, the address environment will
 *   automatically be freed when the module exits.
 *
 * Input Parameters:
 *   loadinfo - Load state information
 *
 * Returned Value:
 *   None.
 *
 ****************************************************************************/

void elf_addrenv_free(FAR struct elf_loadinfo_s *loadinfo)
{
#ifdef CONFIG_ADDRENV
  int ret;

  /* Free the address environemnt */

  ret = up_addrenv_destroy(loadinfo->addrenv);
  if (ret < 0)
    {
      bdbg("ERROR: up_addrenv_destroy failed: %d\n", ret);
    }

  /* Clear out all indications of the allocated address environment */

  loadinfo->elfalloc = 0;
  loadinfo->elfsize  = 0;
  loadinfo->addrenv  = 0;
#else
  /* If there is an allocation for the ELF image, free it */

  if (loadinfo->elfalloc != 0)
    {
      kfree((FAR void *)loadinfo->elfalloc);
      loadinfo->elfalloc = 0;
    }

   loadinfo->elfsize = 0;
#endif
}