1 /* Update symbol information and section index in symbol table at the
2 given index.
3 Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014, 2015 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(Elf_Data * symdata,Elf_Data * shndxdata,int ndx,GElf_Sym * src,Elf32_Word srcshndx)43 gelf_update_symshndx (Elf_Data *symdata, Elf_Data *shndxdata, int ndx,
44 GElf_Sym *src, Elf32_Word srcshndx)
45 {
46 Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata;
47 Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata;
48 Elf_Scn *scn;
49 Elf32_Word *shndx = NULL;
50 int result = 0;
51
52 if (symdata == NULL)
53 return 0;
54
55 if (unlikely (symdata_scn->d.d_type != ELF_T_SYM))
56 {
57 /* The type of the data better should match. */
58 __libelf_seterrno (ELF_E_DATA_MISMATCH);
59 return 0;
60 }
61
62 scn = symdata_scn->s;
63 /* We simply have to believe the user that the two sections belong to
64 the same ELF file. */
65 rwlock_wrlock (scn->elf->lock);
66
67 /* The user is not required to pass a data descriptor for an extended
68 section index table. */
69 if (shndxdata_scn != NULL)
70 {
71 if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size))
72 {
73 __libelf_seterrno (ELF_E_INVALID_INDEX);
74 goto out;
75 }
76
77 shndx = &((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx];
78 }
79 /* But if s/he does not the extended sectio index must be zero. */
80 else if (unlikely (srcshndx != 0))
81 {
82 __libelf_seterrno (ELF_E_INVALID_INDEX);
83 goto out;
84 }
85
86 if (scn->elf->class == ELFCLASS32)
87 {
88 Elf32_Sym *sym;
89
90 /* There is the possibility that the values in the input are
91 too large. */
92 if (unlikely (src->st_value > 0xffffffffull)
93 || unlikely (src->st_size > 0xffffffffull))
94 {
95 __libelf_seterrno (ELF_E_INVALID_DATA);
96 goto out;
97 }
98
99 /* Check whether we have to resize the data buffer. */
100 if (INVALID_NDX (ndx, Elf32_Sym, &symdata_scn->d))
101 {
102 __libelf_seterrno (ELF_E_INVALID_INDEX);
103 goto out;
104 }
105
106 sym = &((Elf32_Sym *) symdata_scn->d.d_buf)[ndx];
107
108 #define COPY(name) \
109 sym->name = src->name
110 COPY (st_name);
111 COPY (st_value);
112 COPY (st_size);
113 /* Please note that we can simply copy the `st_info' element since
114 the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
115 for the 64 bit variant. */
116 COPY (st_info);
117 COPY (st_other);
118 COPY (st_shndx);
119 }
120 else
121 {
122 /* Check whether we have to resize the data buffer. */
123 if (INVALID_NDX (ndx, Elf64_Sym, &symdata_scn->d))
124 {
125 __libelf_seterrno (ELF_E_INVALID_INDEX);
126 goto out;
127 }
128
129 ((Elf64_Sym *) symdata_scn->d.d_buf)[ndx] = *src;
130 }
131
132 /* Now we can store the section index. */
133 if (shndx != NULL)
134 *shndx = srcshndx;
135
136 result = 1;
137
138 /* Mark the section as modified. */
139 scn->flags |= ELF_F_DIRTY;
140
141 out:
142 rwlock_unlock (scn->elf->lock);
143
144 return result;
145 }
146