1 /*
2 * Copyright (C) 2018 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 extern "C" int getRandomNumber();
18
19 class B {
20 public:
getBiggerRandomNumber()21 virtual int getBiggerRandomNumber() {
22 // Call to the other library.
23 return getRandomNumber() * 2;
24 }
25
~B()26 virtual ~B() {}
27 };
28
29 B b;
30
31 // nested macros to make it easy to define a large amount of read-only data
32 // which will require relocation.
33 #define B_16 &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b, &b,
34 #define B_128 B_16 B_16 B_16 B_16 B_16 B_16 B_16 B_16
35 #define B_1024 B_128 B_128 B_128 B_128 B_128 B_128 B_128 B_128
36
37 extern "C" B* const lots_more_relro[] = {
38 B_1024 B_1024 B_1024 B_1024 B_1024 B_1024 B_1024 B_1024
39 };
40
getBiggerRandomNumber()41 extern "C" int getBiggerRandomNumber() {
42 // access the relro section (twice, in fact, once for the pointer, and once
43 // for the vtable of B) to check it's actually there.
44 return lots_more_relro[0]->getBiggerRandomNumber();
45 }
46