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
|
/*
SPDX-License-Identifier: GPL-2.0-only
Copyright (C) 2009 Red Hat Inc.
Copyright (C) 2009 Arnaldo Carvalho de Melo <acme@redhat.com>
*/
#include <malloc.h>
#include <stdio.h>
#include <string.h>
#include "dutil.h"
#include "elf_symtab.h"
#define HASHSYMS__BITS 8
#define HASHSYMS__SIZE (1UL << HASHSYMS__BITS)
struct elf_symtab *elf_symtab__new(const char *name, Elf *elf)
{
size_t symtab_index;
if (name == NULL)
name = ".symtab";
GElf_Shdr shdr;
Elf_Scn *sec = elf_section_by_name(elf, &shdr, name, &symtab_index);
if (sec == NULL)
return NULL;
if (gelf_getshdr(sec, &shdr) == NULL)
return NULL;
struct elf_symtab *symtab = zalloc(sizeof(*symtab));
if (symtab == NULL)
return NULL;
symtab->name = strdup(name);
if (symtab->name == NULL)
goto out_delete;
symtab->syms = elf_getdata(sec, NULL);
if (symtab->syms == NULL)
goto out_free_name;
/*
* This returns extended section index table's
* section index, if it exists.
*/
int symtab_xindex = elf_scnshndx(sec);
sec = elf_getscn(elf, shdr.sh_link);
if (sec == NULL)
goto out_free_name;
symtab->symstrs = elf_getdata(sec, NULL);
if (symtab->symstrs == NULL)
goto out_free_name;
/*
* The .symtab section has optional extended section index
* table, load its data so it can be used to resolve symbol's
* section index.
**/
if (symtab_xindex > 0) {
GElf_Shdr shdr_xindex;
Elf_Scn *sec_xindex;
sec_xindex = elf_getscn(elf, symtab_xindex);
if (sec_xindex == NULL)
goto out_free_name;
if (gelf_getshdr(sec_xindex, &shdr_xindex) == NULL)
goto out_free_name;
/* Extra check to verify it's correct type */
if (shdr_xindex.sh_type != SHT_SYMTAB_SHNDX)
goto out_free_name;
/* Extra check to verify it belongs to the .symtab */
if (symtab_index != shdr_xindex.sh_link)
goto out_free_name;
symtab->syms_sec_idx_table = elf_getdata(elf_getscn(elf, symtab_xindex), NULL);
if (symtab->syms_sec_idx_table == NULL)
goto out_free_name;
}
symtab->nr_syms = shdr.sh_size / shdr.sh_entsize;
return symtab;
out_free_name:
zfree(&symtab->name);
out_delete:
free(symtab);
return NULL;
}
void elf_symtab__delete(struct elf_symtab *symtab)
{
if (symtab == NULL)
return;
zfree(&symtab->name);
free(symtab);
}
|