| // Copyright 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/trace_event/heap_profiler_allocation_register.h" |
| |
| #include <stddef.h> |
| #include <sys/mman.h> |
| #include <unistd.h> |
| |
| #include "base/bits.h" |
| #include "base/logging.h" |
| #include "base/process/process_metrics.h" |
| |
| #ifndef MAP_ANONYMOUS |
| #define MAP_ANONYMOUS MAP_ANON |
| #endif |
| |
| namespace base { |
| namespace trace_event { |
| namespace internal { |
| |
| namespace { |
| size_t GetGuardSize() { |
| return GetPageSize(); |
| } |
| } |
| |
| void* AllocateGuardedVirtualMemory(size_t size) { |
| size = bits::Align(size, GetPageSize()); |
| |
| // Add space for a guard page at the end. |
| size_t map_size = size + GetGuardSize(); |
| |
| void* addr = mmap(nullptr, map_size, PROT_READ | PROT_WRITE, |
| MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| |
| PCHECK(addr != MAP_FAILED); |
| |
| // Mark the last page of the allocated address space as inaccessible |
| // (PROT_NONE). The read/write accessible space is still at least |min_size| |
| // bytes. |
| void* guard_addr = |
| reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(addr) + size); |
| int result = mprotect(guard_addr, GetGuardSize(), PROT_NONE); |
| PCHECK(result == 0); |
| |
| return addr; |
| } |
| |
| void FreeGuardedVirtualMemory(void* address, size_t allocated_size) { |
| size_t size = bits::Align(allocated_size, GetPageSize()) + GetGuardSize(); |
| munmap(address, size); |
| } |
| |
| } // namespace internal |
| } // namespace trace_event |
| } // namespace base |