nuttx/libs/libc/modlib/modlib_init.c

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/****************************************************************************
* libs/libc/modlib/modlib_init.c
*
* Copyright (C) 2015, 2017-2018 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 <sys/stat.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/lib/modlib.h>
#include "modlib/modlib.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* CONFIG_DEBUG_FEATURES, CONFIG_DEBUG_INFO, and CONFIG_MODLIB_DUMPBUFFER
* have to be defined or CONFIG_MODLIB_DUMPBUFFER does nothing.
*/
#if !defined(CONFIG_DEBUG_INFO) || !defined (CONFIG_MODLIB_DUMPBUFFER)
# undef CONFIG_MODLIB_DUMPBUFFER
#endif
#ifdef CONFIG_MODLIB_DUMPBUFFER
# define modlib_dumpbuffer(m,b,n) binfodumpbuffer(m,b,n)
#else
# define modlib_dumpbuffer(m,b,n)
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: modlib_filelen
*
* Description:
* Get the size of the ELF file
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
static inline int modlib_filelen(FAR struct mod_loadinfo_s *loadinfo,
FAR const char *filename)
{
struct stat buf;
int ret;
/* Get the file stats */
ret = stat(filename, &buf);
if (ret < 0)
{
int errval = get_errno();
berr("ERROR: Failed to stat file: %d\n", errval);
return -errval;
}
/* Verify that it is a regular file */
if (!S_ISREG(buf.st_mode))
{
berr("ERROR: Not a regular file. mode: %d\n", buf.st_mode);
return -ENOENT;
}
/* TODO: Verify that the file is readable. Not really important because
* we will detect this when we try to open the file read-only.
*/
/* Return the size of the file in the loadinfo structure */
loadinfo->filelen = buf.st_size;
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: modlib_initialize
*
* Description:
* This function is called to configure the library to process an ELF
* program binary.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_initialize(FAR const char *filename,
FAR struct mod_loadinfo_s *loadinfo)
{
int ret;
binfo("filename: %s loadinfo: %p\n", filename, loadinfo);
/* Clear the load info structure */
memset(loadinfo, 0, sizeof(struct mod_loadinfo_s));
/* Get the length of the file. */
ret = modlib_filelen(loadinfo, filename);
if (ret < 0)
{
berr("ERROR: modlib_filelen failed: %d\n", ret);
return ret;
}
/* Open the binary file for reading (only) */
loadinfo->filfd = _NX_OPEN(filename, O_RDONLY);
if (loadinfo->filfd < 0)
{
int errval = _NX_GETERRNO(loadinfo->filfd);
berr("ERROR: Failed to open ELF binary %s: %d\n", filename, errval);
return -errval;
}
/* Read the ELF ehdr from offset 0 */
ret = modlib_read(loadinfo, (FAR uint8_t *)&loadinfo->ehdr,
sizeof(Elf32_Ehdr), 0);
if (ret < 0)
{
berr("ERROR: Failed to read ELF header: %d\n", ret);
return ret;
}
modlib_dumpbuffer("ELF header", (FAR const uint8_t *)&loadinfo->ehdr,
sizeof(Elf32_Ehdr));
/* Verify the ELF header */
ret = modlib_verifyheader(&loadinfo->ehdr);
if (ret < 0)
{
/* This may not be an error because we will be called to attempt loading
* EVERY binary. If modlib_verifyheader() does not recognize the ELF header,
* it will -ENOEXEC whcih simply informs the system that the file is not an
* ELF file. modlib_verifyheader() will return other errors if the ELF header
* is not correctly formed.
*/
berr("ERROR: Bad ELF header: %d\n", ret);
return ret;
}
return OK;
}