aboutsummaryrefslogtreecommitdiff
path: root/nuttx/binfmt/libelf/libelf_init.c
blob: a3a320b16503af9cf73a5e817ca5517ef230b258 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/****************************************************************************
 * binfmt/libelf/libelf_init.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 <sys/stat.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <elf.h>
#include <debug.h>
#include <errno.h>

#include <nuttx/binfmt/elf.h>

#include "libelf.h"

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

/* CONFIG_DEBUG, CONFIG_DEBUG_VERBOSE, and CONFIG_DEBUG_BINFMT have to be
 * defined or CONFIG_ELF_DUMPBUFFER does nothing.
 */

#if !defined(CONFIG_DEBUG_VERBOSE) || !defined (CONFIG_DEBUG_BINFMT)
#  undef CONFIG_ELF_DUMPBUFFER
#endif

#ifdef CONFIG_ELF_DUMPBUFFER
# define elf_dumpbuffer(m,b,n) bvdbgdumpbuffer(m,b,n)
#else
# define elf_dumpbuffer(m,b,n)
#endif

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

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

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

/****************************************************************************
 * Name: elf_init
 *
 * 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 elf_init(FAR const char *filename, FAR struct elf_loadinfo_s *loadinfo)
{
  int ret;

  bvdbg("filename: %s loadinfo: %p\n", filename, loadinfo);

  /* Clear the load info structure */

  memset(loadinfo, 0, sizeof(struct elf_loadinfo_s));

  /* Open the binary file */

  loadinfo->filfd = open(filename, O_RDONLY);
  if (loadinfo->filfd < 0)
    {
      int errval = errno;
      bdbg("Failed to open ELF binary %s: %d\n", filename, errval);
      return -errval;      
    }

  /* Read the ELF ehdr from offset 0 */

  ret = elf_read(loadinfo, (FAR uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr), 0);
  if (ret < 0)
    {
      bdbg("Failed to read ELF header: %d\n", ret);
      return ret;
    }

  elf_dumpbuffer("ELF header", (FAR const uint8_t*)&loadinfo->ehdr, sizeof(Elf32_Ehdr));

  /* Verify the ELF header */

  ret = elf_verifyheader(&loadinfo->ehdr);
  if (ret <0)
    {
      /* This may not be an error because we will be called to attempt loading
       * EVERY binary.  If elf_verifyheader() does not recognize the ELF header,
       * it will -ENOEXEC whcih simply informs the system that the file is not an
       * ELF file.  elf_verifyheader() will return other errors if the ELF header
       * is not correctly formed.
       */

      bdbg("Bad ELF header: %d\n", ret);
      return ret;
    }

  return OK;
}