| // Copyright (c) 2006, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| // |
| // ProtectedMemoryAllocator |
| // |
| // See the header file for documentation |
| |
| #include "protected_memory_allocator.h" |
| #include <assert.h> |
| |
| //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| ProtectedMemoryAllocator::ProtectedMemoryAllocator(vm_size_t pool_size) |
| : pool_size_(pool_size), |
| next_alloc_offset_(0), |
| valid_(false) { |
| |
| kern_return_t result = vm_allocate(mach_task_self(), |
| &base_address_, |
| pool_size, |
| TRUE |
| ); |
| |
| valid_ = (result == KERN_SUCCESS); |
| assert(valid_); |
| } |
| |
| //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| ProtectedMemoryAllocator::~ProtectedMemoryAllocator() { |
| vm_deallocate(mach_task_self(), |
| base_address_, |
| pool_size_ |
| ); |
| } |
| |
| //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| char *ProtectedMemoryAllocator::Allocate(vm_size_t bytes) { |
| if (valid_ && next_alloc_offset_ + bytes <= pool_size_) { |
| char *p = (char*)base_address_ + next_alloc_offset_; |
| next_alloc_offset_ += bytes; |
| return p; |
| } |
| |
| return NULL; // ran out of memory in our allocation block |
| } |
| |
| //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| kern_return_t ProtectedMemoryAllocator::Protect() { |
| kern_return_t result = vm_protect(mach_task_self(), |
| base_address_, |
| pool_size_, |
| FALSE, |
| VM_PROT_READ); |
| |
| return result; |
| } |
| |
| //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| kern_return_t ProtectedMemoryAllocator::Unprotect() { |
| kern_return_t result = vm_protect(mach_task_self(), |
| base_address_, |
| pool_size_, |
| FALSE, |
| VM_PROT_READ | VM_PROT_WRITE); |
| |
| return result; |
| } |
