| /* | |
| * 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. | |
| */ | |
| #pragma once | |
| #define US_PER_S 1'000'000LL | |
| #define NS_PER_S 1'000'000'000LL | |
| // Size of the shadow call stack. This can be small because these stacks only | |
| // contain return addresses. This must be a power of 2 so the mask trick works. | |
| // See the SCS commentary in pthread_internal.h for more detail. | |
| // SCS_SIZE must be a multiple of page size. | |
| // We used 8KiB until V but switched to 16KiB in V to experiment with 16KiB pages. | |
| #define SCS_SIZE (16 * 1024) | |
| #define SCS_MASK (SCS_SIZE - 1) | |
| // The shadow call stack is allocated at an aligned address within a guard region of this size. The | |
| // guard region must be large enough that we can allocate an SCS_SIZE-aligned SCS while ensuring | |
| // that there is at least one guard page after the SCS so that a stack overflow results in a SIGSEGV | |
| // instead of corrupting the allocation that comes after it. | |
| #define SCS_GUARD_REGION_SIZE (16 * 1024 * 1024) |