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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* Return converted data from raw chunk of ELF file.
Copyright (C) 2007, 2014, 2015 Red Hat, Inc.
Copyright (C) 2022 Mark J. Wielaard <mark@klomp.org>
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
it under the terms of either
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at
your option) any later version
or
* the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at
your option) any later version
or both in parallel, as here.
elfutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received copies of the GNU General Public License and
the GNU Lesser General Public License along with this program. If
not, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "libelfP.h"
#include "common.h"
Elf_Data *
elf_getdata_rawchunk (Elf *elf, int64_t offset, size_t size, Elf_Type type)
{
if (unlikely (elf == NULL))
return NULL;
if (unlikely (elf->kind != ELF_K_ELF))
{
/* No valid descriptor. */
__libelf_seterrno (ELF_E_INVALID_HANDLE);
return NULL;
}
if (unlikely (offset < 0 || (uint64_t) offset > elf->maximum_size
|| elf->maximum_size - (uint64_t) offset < size))
{
/* Invalid request. */
__libelf_seterrno (ELF_E_INVALID_OP);
return NULL;
}
if (type >= ELF_T_NUM)
{
__libelf_seterrno (ELF_E_UNKNOWN_TYPE);
return NULL;
}
/* Get the raw bytes from the file. */
void *rawchunk;
int flags = 0;
Elf_Data *result = NULL;
rwlock_rdlock (elf->lock);
/* Maybe we already got this chunk? */
Elf_Data_Chunk *rawchunks = elf->state.elf.rawchunks;
while (rawchunks != NULL)
{
if ((rawchunks->offset == offset || size == 0)
&& rawchunks->data.d.d_size == size
&& rawchunks->data.d.d_type == type)
{
result = &rawchunks->data.d;
goto out;
}
rawchunks = rawchunks->next;
}
size_t align = __libelf_type_align (elf->class, type);
if (elf->map_address != NULL)
{
/* If the file is mmap'ed we can use it directly, if aligned for type. */
char *rawdata = elf->map_address + elf->start_offset + offset;
if (((uintptr_t) rawdata & (align - 1)) == 0)
rawchunk = rawdata;
else
{
/* We allocate the memory and memcpy it to get aligned data. */
rawchunk = malloc (size);
if (rawchunk == NULL)
goto nomem;
memcpy (rawchunk, rawdata, size);
flags = ELF_F_MALLOCED;
}
}
else
{
/* We allocate the memory and read the data from the file. */
rawchunk = malloc (size);
if (rawchunk == NULL)
{
nomem:
__libelf_seterrno (ELF_E_NOMEM);
goto out;
}
/* Read the file content. */
if (unlikely ((size_t) pread_retry (elf->fildes, rawchunk, size,
elf->start_offset + offset)
!= size))
{
/* Something went wrong. */
free (rawchunk);
__libelf_seterrno (ELF_E_READ_ERROR);
goto out;
}
flags = ELF_F_MALLOCED;
}
/* Copy and/or convert the data as needed for aligned native-order access. */
void *buffer;
if (elf->state.elf32.ehdr->e_ident[EI_DATA] == MY_ELFDATA)
{
if (((uintptr_t) rawchunk & (align - 1)) == 0)
/* No need to copy, we can use the raw data. */
buffer = rawchunk;
else
{
/* A malloc'd block is always sufficiently aligned. */
assert (flags == 0);
buffer = malloc (size);
if (unlikely (buffer == NULL))
goto nomem;
flags = ELF_F_MALLOCED;
/* The copy will be appropriately aligned for direct access. */
memcpy (buffer, rawchunk, size);
}
}
else
{
if (flags)
buffer = rawchunk;
else
{
buffer = malloc (size);
if (unlikely (buffer == NULL))
goto nomem;
flags = ELF_F_MALLOCED;
}
/* Call the conversion function. */
(*__elf_xfctstom[elf->class - 1][type])(buffer, rawchunk, size, 0);
}
/* Allocate the dummy container to point at this buffer. */
Elf_Data_Chunk *chunk = calloc (1, sizeof *chunk);
if (chunk == NULL)
{
if (flags)
free (buffer);
goto nomem;
}
chunk->dummy_scn.elf = elf;
chunk->dummy_scn.flags = flags;
chunk->data.s = &chunk->dummy_scn;
chunk->data.d.d_buf = buffer;
chunk->data.d.d_size = size;
chunk->data.d.d_type = type;
chunk->data.d.d_align = align;
chunk->data.d.d_version = EV_CURRENT;
chunk->offset = offset;
rwlock_unlock (elf->lock);
rwlock_wrlock (elf->lock);
chunk->next = elf->state.elf.rawchunks;
elf->state.elf.rawchunks = chunk;
result = &chunk->data.d;
out:
rwlock_unlock (elf->lock);
return result;
}
|
