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
|
// target-reloc.h -- target specific relocation support -*- C++ -*-
// Copyright 2006, 2007 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// 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 3 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., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#ifndef GOLD_TARGET_RELOC_H
#define GOLD_TARGET_RELOC_H
#include "elfcpp.h"
#include "symtab.h"
#include "reloc-types.h"
namespace gold
{
// This function implements the generic part of reloc scanning. This
// is an inline function which takes a class whose member functions
// local() and global() implement the machine specific part of scanning.
// We do it this way to avoidmaking a function call for each relocation,
// and to avoid repeating the generic code for each target.
template<int size, bool big_endian, typename Target_type, int sh_type,
typename Scan>
inline void
scan_relocs(
const General_options& options,
Symbol_table* symtab,
Layout* layout,
Target_type* target,
Sized_relobj<size, big_endian>* object,
unsigned int data_shndx,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
bool needs_special_offset_handling,
size_t local_count,
const unsigned char* plocal_syms)
{
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
Scan scan;
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
if (needs_special_offset_handling
&& !output_section->is_input_address_mapped(object, data_shndx,
reloc.get_r_offset()))
continue;
typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
if (r_sym < local_count)
{
gold_assert(plocal_syms != NULL);
typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
+ r_sym * sym_size);
const unsigned int shndx = lsym.get_st_shndx();
if (shndx < elfcpp::SHN_LORESERVE
&& shndx != elfcpp::SHN_UNDEF
&& !object->is_section_included(lsym.get_st_shndx()))
{
// RELOC is a relocation against a local symbol in a
// section we are discarding. We can ignore this
// relocation. It will eventually become a reloc
// against the value zero.
//
// FIXME: We should issue a warning if this is an
// allocated section; is this the best place to do it?
//
// FIXME: The old GNU linker would in some cases look
// for the linkonce section which caused this section to
// be discarded, and, if the other section was the same
// size, change the reloc to refer to the other section.
// That seems risky and weird to me, and I don't know of
// any case where it is actually required.
continue;
}
scan.local(options, symtab, layout, target, object, data_shndx,
output_section, reloc, r_type, lsym);
}
else
{
Symbol* gsym = object->global_symbol(r_sym);
gold_assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = symtab->resolve_forwards(gsym);
scan.global(options, symtab, layout, target, object, data_shndx,
output_section, reloc, r_type, gsym);
}
}
}
// This function implements the generic part of relocation processing.
// This is an inline function which take a class whose relocate()
// implements the machine specific part of relocation. We do it this
// way to avoid making a function call for each relocation, and to
// avoid repeating the generic relocation handling code for each
// target.
// SIZE is the ELF size: 32 or 64. BIG_ENDIAN is the endianness of
// the data. SH_TYPE is the section type: SHT_REL or SHT_RELA.
// RELOCATE implements operator() to do a relocation.
// PRELOCS points to the relocation data. RELOC_COUNT is the number
// of relocs. OUTPUT_SECTION is the output section.
// NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
// mapped to output offsets.
// VIEW is the section data, VIEW_ADDRESS is its memory address, and
// VIEW_SIZE is the size. These refer to the input section, unless
// NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
// the output section.
template<int size, bool big_endian, typename Target_type, int sh_type,
typename Relocate>
inline void
relocate_section(
const Relocate_info<size, big_endian>* relinfo,
Target_type* target,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
bool needs_special_offset_handling,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
off_t view_size)
{
typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
Relocate relocate;
Sized_relobj<size, big_endian>* object = relinfo->object;
unsigned int local_count = object->local_symbol_count();
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
off_t offset = reloc.get_r_offset();
if (needs_special_offset_handling)
{
offset = output_section->output_offset(relinfo->object,
relinfo->data_shndx,
offset);
if (offset == -1)
continue;
}
typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
const Sized_symbol<size>* sym;
Symbol_value<size> symval;
const Symbol_value<size> *psymval;
if (r_sym < local_count)
{
sym = NULL;
psymval = object->local_symbol(r_sym);
}
else
{
const Symbol* gsym = object->global_symbol(r_sym);
gold_assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = relinfo->symtab->resolve_forwards(gsym);
sym = static_cast<const Sized_symbol<size>*>(gsym);
if (sym->has_symtab_index())
symval.set_output_symtab_index(sym->symtab_index());
else
symval.set_no_output_symtab_entry();
symval.set_output_value(sym->value());
psymval = &symval;
}
if (!relocate.relocate(relinfo, target, i, reloc, r_type, sym, psymval,
view + offset, view_address + offset, view_size))
continue;
if (offset < 0 || offset >= view_size)
{
gold_error_at_location(relinfo, i, offset,
_("reloc has bad offset %zu"),
static_cast<size_t>(offset));
continue;
}
if (sym != NULL
&& sym->is_undefined()
&& sym->binding() != elfcpp::STB_WEAK
&& !parameters->output_is_shared())
gold_undefined_symbol(sym, relinfo, i, offset);
if (sym != NULL && sym->has_warning())
relinfo->symtab->issue_warning(sym, relinfo, i, offset);
}
}
} // End namespace gold.
#endif // !defined(GOLD_TARGET_RELOC_H)
|
