1 /*
2 * Copyright 2011, The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ELF_SECTION_REL_TABLE_HXX
18 #define ELF_SECTION_REL_TABLE_HXX
19
20 #include "ELF.h"
21 #include "ELFHeader.h"
22 #include "ELFObject.h"
23 #include "ELFReloc.h"
24 #include "ELFTypes.h"
25
26 #include <set>
27
28 template <unsigned Bitwidth>
~ELFSectionRelTable()29 ELFSectionRelTable<Bitwidth>::~ELFSectionRelTable() {
30 using namespace std;
31 for (size_t i = 0; i < table.size(); ++i) {
32 delete table[i];
33 }
34 }
35
36 template <unsigned Bitwidth>
print() const37 void ELFSectionRelTable<Bitwidth>::print() const {
38 using namespace llvm;
39
40 out() << '\n' << fillformat('=', 79) << '\n';
41 out().changeColor(raw_ostream::WHITE, true);
42 out() << "Relocation Table" << '\n';
43 out().resetColor();
44
45 for (size_t i = 0; i < this->size(); ++i) {
46 (*this)[i]->print();
47 }
48
49 out() << fillformat('=', 79) << '\n';
50 }
51
52 template <unsigned Bitwidth>
53 template <typename Archiver>
54 ELFSectionRelTable<Bitwidth> *
read(Archiver & AR,ELFSectionHeaderTy const * sh)55 ELFSectionRelTable<Bitwidth>::read(Archiver &AR,
56 ELFSectionHeaderTy const *sh) {
57
58 rsl_assert(sh->getType() == SHT_REL || sh->getType() == SHT_RELA);
59
60 std::unique_ptr<ELFSectionRelTable> rt(new ELFSectionRelTable());
61
62 // Seek to the start of the table
63 AR.seek(sh->getOffset(), true);
64
65 // Count the relocation entries
66 size_t size = sh->getSize() / sh->getEntrySize();
67
68 // Read every relocation entries
69 if (sh->getType() == SHT_REL) {
70 rsl_assert(sh->getEntrySize() == TypeTraits<ELFRelocRelTy>::size);
71 for (size_t i = 0; i < size; ++i) {
72 rt->table.push_back(ELFRelocTy::readRel(AR, i));
73 }
74
75 } else {
76 rsl_assert(sh->getEntrySize() == TypeTraits<ELFRelocRelaTy>::size);
77 for (size_t i = 0; i < size; ++i) {
78 rt->table.push_back(ELFRelocTy::readRela(AR, i));
79 }
80 }
81
82 if (!AR) {
83 // Unable to read the table.
84 return 0;
85 }
86
87 return rt.release();
88 }
89
90 template <unsigned Bitwidth>
91 size_t ELFSectionRelTable<Bitwidth>::
getMaxNumStubs(ELFObjectTy const * obj) const92 getMaxNumStubs(ELFObjectTy const *obj) const {
93 switch (obj->getHeader()->getMachine()) {
94 case EM_ARM:
95 {
96 std::set<uint32_t> sym_index_set;
97
98 for (size_t i = 0; i < size(); ++i) {
99 ELFRelocTy *rel = table[i];
100
101 switch (rel->getType()) {
102 case R_ARM_CALL:
103 case R_ARM_THM_CALL:
104 case R_ARM_JUMP24:
105 case R_ARM_THM_JUMP24:
106 sym_index_set.insert(rel->getSymTabIndex());
107 break;
108 }
109 }
110
111 return sym_index_set.size();
112 }
113
114 case EM_AARCH64:
115 {
116 std::set<uint32_t> sym_index_set;
117
118 for (size_t i = 0; i < size(); ++i) {
119 ELFRelocTy *rel = table[i];
120
121 switch (rel->getType()) {
122 case R_AARCH64_CALL26:
123 case R_AARCH64_JUMP26:
124 sym_index_set.insert(rel->getSymTabIndex());
125 break;
126 }
127 }
128
129 return sym_index_set.size();
130 }
131
132 case EM_MIPS:
133 {
134 std::set<uint32_t> sym_index_set;
135
136 for (size_t i = 0; i < size(); ++i) {
137 ELFRelocTy *rel = table[i];
138
139 if (rel->getType() == R_MIPS_26) {
140 sym_index_set.insert(rel->getSymTabIndex());
141 }
142 }
143
144 return sym_index_set.size();
145 }
146
147 case EM_386:
148 case EM_X86_64:
149 return 0;
150
151 default:
152 rsl_assert(0 && "Only support ARM, MIPS, X86, and X86_64 relocation.");
153 return 0;
154 }
155 }
156
157 #endif // ELF_SECTION_REL_TABLE_HXX
158