1/* Return converted data from raw chunk of ELF file.
2   Copyright (C) 2007 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4
5   Red Hat elfutils is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by the
7   Free Software Foundation; version 2 of the License.
8
9   Red Hat elfutils is distributed in the hope that it will be useful, but
10   WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with Red Hat elfutils; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18   In addition, as a special exception, Red Hat, Inc. gives You the
19   additional right to link the code of Red Hat elfutils with code licensed
20   under any Open Source Initiative certified open source license
21   (http://www.opensource.org/licenses/index.php) which requires the
22   distribution of source code with any binary distribution and to
23   distribute linked combinations of the two.  Non-GPL Code permitted under
24   this exception must only link to the code of Red Hat elfutils through
25   those well defined interfaces identified in the file named EXCEPTION
26   found in the source code files (the "Approved Interfaces").  The files
27   of Non-GPL Code may instantiate templates or use macros or inline
28   functions from the Approved Interfaces without causing the resulting
29   work to be covered by the GNU General Public License.  Only Red Hat,
30   Inc. may make changes or additions to the list of Approved Interfaces.
31   Red Hat's grant of this exception is conditioned upon your not adding
32   any new exceptions.  If you wish to add a new Approved Interface or
33   exception, please contact Red Hat.  You must obey the GNU General Public
34   License in all respects for all of the Red Hat elfutils code and other
35   code used in conjunction with Red Hat elfutils except the Non-GPL Code
36   covered by this exception.  If you modify this file, you may extend this
37   exception to your version of the file, but you are not obligated to do
38   so.  If you do not wish to provide this exception without modification,
39   you must delete this exception statement from your version and license
40   this file solely under the GPL without exception.
41
42   Red Hat elfutils is an included package of the Open Invention Network.
43   An included package of the Open Invention Network is a package for which
44   Open Invention Network licensees cross-license their patents.  No patent
45   license is granted, either expressly or impliedly, by designation as an
46   included package.  Should you wish to participate in the Open Invention
47   Network licensing program, please visit www.openinventionnetwork.com
48   <http://www.openinventionnetwork.com>.  */
49
50#ifdef HAVE_CONFIG_H
51# include <config.h>
52#endif
53
54#include <assert.h>
55#include <errno.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include <system.h>
61#include "libelfP.h"
62#include "common.h"
63
64Elf_Data *
65elf_getdata_rawchunk (elf, offset, size, type)
66     Elf *elf;
67     /* ANDROID_CHANGE_BEGIN */
68#if 0
69     off64_t offset;
70#else
71     off_t offset;
72#endif
73     /* ANDROID_CHANGE_END */
74     size_t size;
75     Elf_Type type;
76{
77  if (unlikely (elf == NULL))
78    return NULL;
79
80  if (unlikely (elf->kind != ELF_K_ELF))
81    {
82      /* No valid descriptor.  */
83      __libelf_seterrno (ELF_E_INVALID_HANDLE);
84      return NULL;
85    }
86
87   /* ANDROID_CHANGE_BEGIN */
88#if 0
89  if (unlikely (size > elf->maximum_size
90		|| (off64_t) (elf->maximum_size - size) < offset))
91#else
92  if (unlikely (size > elf->maximum_size
93		|| (off_t) (elf->maximum_size - size) < offset))
94#endif
95   /* ANDROID_CHANGE_END */
96    {
97      /* Invalid request.  */
98      __libelf_seterrno (ELF_E_INVALID_OP);
99      return NULL;
100    }
101
102  if (type >= ELF_T_NUM)
103    {
104      __libelf_seterrno (ELF_E_UNKNOWN_TYPE);
105      return NULL;
106    }
107
108  /* Get the raw bytes from the file.  */
109  void *rawchunk;
110  int flags = 0;
111  Elf_Data *result = NULL;
112
113  rwlock_rdlock (elf->lock);
114
115  /* If the file is mmap'ed we can use it directly.  */
116  if (elf->map_address != NULL)
117    rawchunk = elf->map_address + elf->start_offset + offset;
118  else
119    {
120      /* We allocate the memory and read the data from the file.  */
121      rawchunk = malloc (size);
122      if (rawchunk == NULL)
123	{
124	nomem:
125	  __libelf_seterrno (ELF_E_NOMEM);
126	  goto out;
127	}
128
129      /* Read the file content.  */
130      if (unlikely ((size_t) pread_retry (elf->fildes, rawchunk, size,
131					  elf->start_offset + offset)
132		    != size))
133	{
134	  /* Something went wrong.  */
135	  free (rawchunk);
136	  __libelf_seterrno (ELF_E_READ_ERROR);
137	  goto out;
138	}
139
140      flags = ELF_F_MALLOCED;
141    }
142
143  /* Copy and/or convert the data as needed for aligned native-order access.  */
144  size_t align = __libelf_type_align (elf->class, type);
145  void *buffer;
146  if (elf->state.elf32.ehdr->e_ident[EI_DATA] == MY_ELFDATA)
147    {
148      if (((uintptr_t) rawchunk & (align - 1)) == 0)
149	/* No need to copy, we can use the raw data.  */
150	buffer = rawchunk;
151      else
152	{
153	  /* A malloc'd block is always sufficiently aligned.  */
154	  assert (flags == 0);
155
156	  buffer = malloc (size);
157	  if (unlikely (buffer == NULL))
158	    goto nomem;
159	  flags = ELF_F_MALLOCED;
160
161	  /* The copy will be appropriately aligned for direct access.  */
162	  memcpy (buffer, rawchunk, size);
163	}
164    }
165  else
166    {
167      if (flags)
168	buffer = rawchunk;
169      else
170	{
171	  buffer = malloc (size);
172	  if (unlikely (buffer == NULL))
173	    goto nomem;
174	  flags = ELF_F_MALLOCED;
175	}
176
177      /* Call the conversion function.  */
178      (*__elf_xfctstom[LIBELF_EV_IDX][LIBELF_EV_IDX][elf->class - 1][type])
179	(buffer, rawchunk, size, 0);
180    }
181
182  /* Allocate the dummy container to point at this buffer.  */
183  Elf_Data_Chunk *chunk = calloc (1, sizeof *chunk);
184  if (chunk == NULL)
185    {
186      if (flags)
187	free (buffer);
188      goto nomem;
189    }
190
191  chunk->dummy_scn.elf = elf;
192  chunk->dummy_scn.flags = flags;
193  chunk->data.s = &chunk->dummy_scn;
194  chunk->data.d.d_buf = buffer;
195  chunk->data.d.d_size = size;
196  chunk->data.d.d_type = type;
197  chunk->data.d.d_align = align;
198  chunk->data.d.d_version = __libelf_version;
199
200  rwlock_unlock (elf->lock);
201  rwlock_wrlock (elf->lock);
202
203  chunk->next = elf->state.elf.rawchunks;
204  elf->state.elf.rawchunks = chunk;
205  result = &chunk->data.d;
206
207 out:
208  rwlock_unlock (elf->lock);
209  return result;
210}
211