gelf_rela.c revision 4484 
1/*-
2 * Copyright (c) 2006 Joseph Koshy
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <limits.h>
28
29#include <assert.h>
30#include "gelf.h"
31
32#include "_libelf.h"
33
34GElf_Rela *
35gelf_getrela(Elf_Data *d, int ndx, GElf_Rela *dst)
36{
37        int ec;
38        Elf *e;
39        Elf_Scn *scn;
40        Elf32_Rela *rela32;
41        Elf64_Rela *rela64;
42        size_t msz;
43        uint32_t sh_type;
44
45        if (d == NULL || ndx < 0 || dst == NULL ||
46            (scn = d->d_scn) == NULL ||
47            (e = scn->s_elf) == NULL) {
48                LIBELF_SET_ERROR(ARGUMENT, 0);
49                return (NULL);
50        }
51
52        ec = e->e_class;
53        assert(ec == ELFCLASS32 || ec == ELFCLASS64);
54
55        if (ec == ELFCLASS32)
56                sh_type = scn->s_shdr.s_shdr32.sh_type;
57        else
58                sh_type = scn->s_shdr.s_shdr64.sh_type;
59
60        if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
61                LIBELF_SET_ERROR(ARGUMENT, 0);
62                return (NULL);
63        }
64
65        msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
66
67        assert(msz > 0);
68
69        if (msz * ndx >= d->d_size) {
70                LIBELF_SET_ERROR(ARGUMENT, 0);
71                return (NULL);
72        }
73
74        if (ec == ELFCLASS32) {
75                rela32 = (Elf32_Rela *) d->d_buf + ndx;
76
77                dst->r_offset = (Elf64_Addr) rela32->r_offset;
78                dst->r_info   = (Elf64_Xword) rela32->r_info;
79                dst->r_addend = (Elf64_Sxword) rela32->r_addend;
80
81        } else {
82
83                rela64 = (Elf64_Rela *) d->d_buf + ndx;
84
85                *dst = *rela64;
86        }
87
88        return (dst);
89}
90
91int
92gelf_update_rela(Elf_Data *d, int ndx, GElf_Rela *dr)
93{
94        int ec;
95        Elf *e;
96        Elf_Scn *scn;
97        Elf32_Rela *rela32;
98        Elf64_Rela *rela64;
99        size_t msz;
100        uint32_t sh_type;
101
102        if (d == NULL || ndx < 0 || dr == NULL ||
103            (scn = d->d_scn) == NULL ||
104            (e = scn->s_elf) == NULL) {
105                LIBELF_SET_ERROR(ARGUMENT, 0);
106                return (0);
107        }
108
109        ec = e->e_class;
110        assert(ec == ELFCLASS32 || ec == ELFCLASS64);
111
112        if (ec == ELFCLASS32)
113                sh_type = scn->s_shdr.s_shdr32.sh_type;
114        else
115                sh_type = scn->s_shdr.s_shdr64.sh_type;
116
117        if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
118                LIBELF_SET_ERROR(ARGUMENT, 0);
119                return (0);
120        }
121
122        msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
123        assert(msz > 0);
124
125        if (msz * ndx >= d->d_size) {
126                LIBELF_SET_ERROR(ARGUMENT, 0);
127                return (0);
128        }
129
130        if (ec == ELFCLASS32) {
131                rela32 = (Elf32_Rela *) d->d_buf + ndx;
132
133                LIBELF_COPY_U32(rela32, dr, r_offset);
134                LIBELF_COPY_U32(rela32, dr, r_info);
135                LIBELF_COPY_S32(rela32, dr, r_addend);
136        } else {
137                rela64 = (Elf64_Rela *) d->d_buf + ndx;
138
139                *rela64 = *dr;
140        }
141
142        return (1);
143}
144