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
|
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
class A {
public:
virtual int getRandomNumber() {
return 4; // chosen by fair dice roll.
// guaranteed to be random.
}
virtual ~A() {}
};
A a;
// nested macros to make it easy to define a large amount of read-only data
// which will require relocation.
#define A_16 &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a, &a,
#define A_128 A_16 A_16 A_16 A_16 A_16 A_16 A_16 A_16
#define A_1024 A_128 A_128 A_128 A_128 A_128 A_128 A_128 A_128
extern "C" A* const lots_of_relro[] = {
A_1024 A_1024 A_1024 A_1024 A_1024 A_1024 A_1024 A_1024
};
extern "C" int getRandomNumber() {
// access the relro section (twice, in fact, once for the pointer, and once
// for the vtable of A) to check it's actually there.
return lots_of_relro[0]->getRandomNumber();
}
|
