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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
/* i386 specific support for Elf loading and relocation.
Copyright 1996, 1997 Linux International.
Contributed by Richard Henderson <rth@tamu.edu>
This file is part of the Linux modutils.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#ident "$Id$"
#include <string.h>
#include <assert.h>
#include <module.h>
#include <obj.h>
#include <util.h>
/*======================================================================*/
struct i386_got_entry
{
int offset;
unsigned offset_done : 1;
unsigned reloc_done : 1;
};
struct i386_file
{
struct obj_file root;
struct obj_section *got;
};
struct i386_symbol
{
struct obj_symbol root;
struct i386_got_entry gotent;
};
/*======================================================================*/
struct obj_file *
arch_new_file (void)
{
struct i386_file *f;
f = xmalloc(sizeof(*f));
f->got = NULL;
return &f->root;
}
struct obj_section *
arch_new_section (void)
{
return xmalloc(sizeof(struct obj_section));
}
struct obj_symbol *
arch_new_symbol (void)
{
struct i386_symbol *sym;
sym = xmalloc(sizeof(*sym));
memset(&sym->gotent, 0, sizeof(sym->gotent));
return &sym->root;
}
int
arch_load_proc_section(struct obj_section *sec, int fp)
{
/* Assume it's just a debugging section that we can safely
ignore ... */
sec->contents = NULL;
return 0;
}
enum obj_reloc
arch_apply_relocation (struct obj_file *f,
struct obj_section *targsec,
struct obj_section *symsec,
struct obj_symbol *sym,
Elf32_Rel *rel,
Elf32_Addr v)
{
struct i386_file *ifile = (struct i386_file *)f;
struct i386_symbol *isym = (struct i386_symbol *)sym;
Elf32_Addr *loc = (Elf32_Addr *)(targsec->contents + rel->r_offset);
Elf32_Addr dot = targsec->header.sh_addr + rel->r_offset;
Elf32_Addr got = ifile->got ? ifile->got->header.sh_addr : 0;
enum obj_reloc ret = obj_reloc_ok;
switch (ELF32_R_TYPE(rel->r_info))
{
case R_386_NONE:
break;
case R_386_32:
*loc += v;
break;
case R_386_PLT32:
case R_386_PC32:
*loc += v - dot;
break;
case R_386_GLOB_DAT:
case R_386_JMP_SLOT:
*loc = v;
break;
case R_386_RELATIVE:
*loc += f->baseaddr;
break;
case R_386_GOTPC:
assert(got != 0);
*loc += got - dot;
break;
case R_386_GOT32:
assert(isym != NULL);
if (!isym->gotent.reloc_done)
{
isym->gotent.reloc_done = 1;
*(Elf32_Addr *)(ifile->got->contents + isym->gotent.offset) = v;
}
*loc += isym->gotent.offset;
break;
case R_386_GOTOFF:
assert(got != 0);
*loc += v - got;
break;
default:
ret = obj_reloc_unhandled;
break;
}
return ret;
}
int
arch_create_got (struct obj_file *f)
{
struct i386_file *ifile = (struct i386_file *)f;
int i, n, offset = 0, gotneeded = 0;
n = ifile->root.header.e_shnum;
for (i = 0; i < n; ++i)
{
struct obj_section *relsec, *symsec, *strsec;
Elf32_Rel *rel, *relend;
Elf32_Sym *symtab;
const char *strtab;
relsec = ifile->root.sections[i];
if (relsec->header.sh_type != SHT_REL)
continue;
symsec = ifile->root.sections[relsec->header.sh_link];
strsec = ifile->root.sections[symsec->header.sh_link];
rel = (Elf32_Rel *)relsec->contents;
relend = rel + (relsec->header.sh_size / sizeof(Elf32_Rel));
symtab = (Elf32_Sym *)symsec->contents;
strtab = (const char *)strsec->contents;
for (; rel < relend; ++rel)
{
Elf32_Sym *extsym;
struct i386_symbol *intsym;
const char *name;
switch (ELF32_R_TYPE(rel->r_info))
{
case R_386_GOTPC:
case R_386_GOTOFF:
gotneeded = 1;
default:
continue;
case R_386_GOT32:
break;
}
extsym = &symtab[ELF32_R_SYM(rel->r_info)];
if (extsym->st_name)
name = strtab + extsym->st_name;
else
name = f->sections[extsym->st_shndx]->name;
intsym = (struct i386_symbol *)obj_find_symbol(&ifile->root, name);
if (!intsym->gotent.offset_done)
{
intsym->gotent.offset_done = 1;
intsym->gotent.offset = offset;
offset += 4;
}
}
}
if (offset > 0 || gotneeded)
ifile->got = obj_create_alloced_section(&ifile->root, ".got", 4, offset);
return 1;
}
int
arch_init_module (struct obj_file *f, struct module *mod)
{
return 1;
}
int
arch_finalize_section_address(struct obj_file *f, Elf32_Addr base)
{
int i, n = f->header.e_shnum;
f->baseaddr = base;
for (i = 0; i < n; ++i)
f->sections[i]->header.sh_addr += base;
return 1;
}
int
arch_archdata (struct obj_file *fin, struct obj_section *sec)
{
return 0;
}
|
