1 /*
2 * Copyright (C) 2012 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 // Deliberately overwrite the stack canary.
modify_stack_protector_test()18 __attribute__((noinline, optnone)) void modify_stack_protector_test() {
19 // We can't use memset here because it's fortified, and we want to test
20 // the line of defense *after* that.
21 // We can't make a constant change, since the existing byte might already have
22 // had that value.
23 char* p = reinterpret_cast<char*>(&p + 1);
24 *p = ~*p;
25 }
26