| // Copyright 2018 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 "components/gwp_asan/client/guarded_page_allocator.h" |
| |
| #include <sys/mman.h> |
| |
| #include "base/logging.h" |
| |
| namespace gwp_asan { |
| namespace internal { |
| |
| void* GuardedPageAllocator::MapRegion() { |
| return mmap(nullptr, RegionSize(), PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, |
| 0); |
| } |
| |
| void GuardedPageAllocator::UnmapRegion() { |
| CHECK(state_.pages_base_addr); |
| int err = |
| munmap(reinterpret_cast<void*>(state_.pages_base_addr), RegionSize()); |
| DPCHECK(err == 0) << "munmap"; |
| (void)err; |
| } |
| |
| void GuardedPageAllocator::MarkPageReadWrite(void* ptr) { |
| int err = mprotect(ptr, state_.page_size, PROT_READ | PROT_WRITE); |
| PCHECK(err == 0) << "mprotect"; |
| } |
| |
| void GuardedPageAllocator::MarkPageInaccessible(void* ptr) { |
| // mmap() a PROT_NONE page over the address to release it to the system, if |
| // we used mprotect() here the system would count pages in the quarantine |
| // against the RSS. |
| void* err = mmap(ptr, state_.page_size, PROT_NONE, |
| MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); |
| PCHECK(err == ptr) << "mmap"; |
| } |
| |
| } // namespace internal |
| } // namespace gwp_asan |