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
64 Elf_Data *
elf_getdata_rawchunk(elf,offset,size,type)65 elf_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