diff options
Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/client/mac/handler/protected_memory_allocator.h')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/client/mac/handler/protected_memory_allocator.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/client/mac/handler/protected_memory_allocator.h b/toolkit/crashreporter/google-breakpad/src/client/mac/handler/protected_memory_allocator.h new file mode 100644 index 000000000..7e188db26 --- /dev/null +++ b/toolkit/crashreporter/google-breakpad/src/client/mac/handler/protected_memory_allocator.h @@ -0,0 +1,85 @@ +// 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 +// +// A very simple allocator class which allows allocation, but not deallocation. +// The allocations can be made read-only with the Protect() method. +// This class is NOT useful as a general-purpose memory allocation system, +// since it does not allow deallocation. It is useful to use for a group +// of allocations which are created in the same time-frame and destroyed +// in the same time-frame. It is useful for making allocations of memory +// which will not need to change often once initialized. This memory can then +// be protected from memory smashers by calling the Protect() method. + +#ifndef PROTECTED_MEMORY_ALLOCATOR_H__ +#define PROTECTED_MEMORY_ALLOCATOR_H__ + +#include <mach/mach.h> + +// +class ProtectedMemoryAllocator { + public: + ProtectedMemoryAllocator(vm_size_t pool_size); + ~ProtectedMemoryAllocator(); + + // Returns a pointer to an allocation of size n within the pool. + // Fails by returning NULL is no more space is available. + // Please note that the pointers returned from this method should not + // be freed in any way (for example by calling free() on them ). + char * Allocate(vm_size_t n); + + // Returns the base address of the allocation pool. + char * GetBaseAddress() { return (char*)base_address_; } + + // Returns the size of the allocation pool, including allocated + // plus free space. + vm_size_t GetTotalSize() { return pool_size_; } + + // Returns the number of bytes already allocated in the pool. + vm_size_t GetAllocatedSize() { return next_alloc_offset_; } + + // Returns the number of bytes available for allocation. + vm_size_t GetFreeSize() { return pool_size_ - next_alloc_offset_; } + + // Makes the entire allocation pool read-only including, of course, + // all allocations made from the pool. + kern_return_t Protect(); + + // Makes the entire allocation pool read/write. + kern_return_t Unprotect(); + + private: + vm_size_t pool_size_; + vm_address_t base_address_; + vm_size_t next_alloc_offset_; + bool valid_; +}; + +#endif // PROTECTED_MEMORY_ALLOCATOR_H__ |