blob: 05914f40016baf07a4b654b10954fe162e68cbd1 [file] [log] [blame]
Elliott Hughes04303f52014-09-18 16:11:59 -07001/*
2 * Copyright (C) 2014 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
Elliott Hughes9a7155d2023-02-10 02:00:03 +000017#pragma once
Elliott Hughes04303f52014-09-18 16:11:59 -070018
19#define NS_PER_S 1000000000
20
Elliott Hughes9a7155d2023-02-10 02:00:03 +000021// Size of the shadow call stack. This can be small because these stacks only
22// contain return addresses. This must be a power of 2 so the mask trick works.
23// See the SCS commentary in pthread_internal.h for more detail.
Kelvin Zhangfb733612023-07-10 15:25:22 -070024// SCS_SIZE must be a multiple of page size.
25// We used 8KiB until V but switched to 16KiB in V to experiment with 16KiB pages.
26#define SCS_SIZE (16 * 1024)
Elliott Hughes9a7155d2023-02-10 02:00:03 +000027#define SCS_MASK (SCS_SIZE - 1)
Peter Collingbourne734beec2018-11-14 12:41:41 -080028
29// The shadow call stack is allocated at an aligned address within a guard region of this size. The
30// guard region must be large enough that we can allocate an SCS_SIZE-aligned SCS while ensuring
31// that there is at least one guard page after the SCS so that a stack overflow results in a SIGSEGV
32// instead of corrupting the allocation that comes after it.
Peter Collingbournef1ed31f2019-01-31 14:26:43 -080033#define SCS_GUARD_REGION_SIZE (16 * 1024 * 1024)