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
42int
43gelf_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