1 /* Update symbol information and section index in symbol table at the
2 given index.
3 Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014 Red Hat, Inc.
4 This file is part of elfutils.
5 Written by Ulrich Drepper <drepper@redhat.com>, 2000.
6
7 This file is free software; you can redistribute it and/or modify
8 it under the terms of either
9
10 * the GNU Lesser General Public License as published by the Free
11 Software Foundation; either version 3 of the License, or (at
12 your option) any later version
13
14 or
15
16 * the GNU General Public License as published by the Free
17 Software Foundation; either version 2 of the License, or (at
18 your option) any later version
19
20 or both in parallel, as here.
21
22 elfutils is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of
24 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 General Public License for more details.
26
27 You should have received copies of the GNU General Public License and
28 the GNU Lesser General Public License along with this program. If
29 not, see <http://www.gnu.org/licenses/>. */
30
31 #ifdef HAVE_CONFIG_H
32 # include <config.h>
33 #endif
34
35 #include <gelf.h>
36 #include <stdlib.h>
37 #include <string.h>
38
39 #include "libelfP.h"
40
41
42 int
gelf_update_symshndx(symdata,shndxdata,ndx,src,srcshndx)43 gelf_update_symshndx (symdata, shndxdata, ndx, src, srcshndx)
44 Elf_Data *symdata;
45 Elf_Data *shndxdata;
46 int ndx;
47 GElf_Sym *src;
48 Elf32_Word srcshndx;
49 {
50 Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata;
51 Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata;
52 Elf_Scn *scn;
53 Elf32_Word *shndx = NULL;
54 int result = 0;
55
56 if (symdata == NULL)
57 return 0;
58
59 if (unlikely (symdata_scn->d.d_type != ELF_T_SYM))
60 {
61 /* The type of the data better should match. */
62 __libelf_seterrno (ELF_E_DATA_MISMATCH);
63 return 0;
64 }
65
66 scn = symdata_scn->s;
67 /* We simply have to believe the user that the two sections belong to
68 the same ELF file. */
69 rwlock_wrlock (scn->elf->lock);
70
71 /* The user is not required to pass a data descriptor for an extended
72 section index table. */
73 if (shndxdata_scn != NULL)
74 {
75 if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size))
76 {
77 __libelf_seterrno (ELF_E_INVALID_INDEX);
78 goto out;
79 }
80
81 shndx = &((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx];
82 }
83 /* But if s/he does not the extended sectio index must be zero. */
84 else if (unlikely (srcshndx != 0))
85 {
86 __libelf_seterrno (ELF_E_INVALID_INDEX);
87 goto out;
88 }
89
90 if (scn->elf->class == ELFCLASS32)
91 {
92 Elf32_Sym *sym;
93
94 /* There is the possibility that the values in the input are
95 too large. */
96 if (unlikely (src->st_value > 0xffffffffull)
97 || unlikely (src->st_size > 0xffffffffull))
98 {
99 __libelf_seterrno (ELF_E_INVALID_DATA);
100 goto out;
101 }
102
103 /* Check whether we have to resize the data buffer. */
104 if (INVALID_NDX (ndx, Elf32_Sym, &symdata_scn->d))
105 {
106 __libelf_seterrno (ELF_E_INVALID_INDEX);
107 goto out;
108 }
109
110 sym = &((Elf32_Sym *) symdata_scn->d.d_buf)[ndx];
111
112 #define COPY(name) \
113 sym->name = src->name
114 COPY (st_name);
115 COPY (st_value);
116 COPY (st_size);
117 /* Please note that we can simply copy the `st_info' element since
118 the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
119 for the 64 bit variant. */
120 COPY (st_info);
121 COPY (st_other);
122 COPY (st_shndx);
123 }
124 else
125 {
126 /* Check whether we have to resize the data buffer. */
127 if (INVALID_NDX (ndx, Elf64_Sym, &symdata_scn->d))
128 {
129 __libelf_seterrno (ELF_E_INVALID_INDEX);
130 goto out;
131 }
132
133 ((Elf64_Sym *) symdata_scn->d.d_buf)[ndx] = *src;
134 }
135
136 /* Now we can store the section index. */
137 if (shndx != NULL)
138 *shndx = srcshndx;
139
140 result = 1;
141
142 /* Mark the section as modified. */
143 scn->flags |= ELF_F_DIRTY;
144
145 out:
146 rwlock_unlock (scn->elf->lock);
147
148 return result;
149 }
150