diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/client/mac/handler/exception_handler.cc | 30 | ||||
| -rw-r--r-- | src/client/mac/handler/protected_memory_allocator.cc | 92 | ||||
| -rw-r--r-- | src/client/mac/handler/protected_memory_allocator.h | 85 |
3 files changed, 207 insertions, 0 deletions
diff --git a/src/client/mac/handler/exception_handler.cc b/src/client/mac/handler/exception_handler.cc index ab2cc489..72e3c811 100644 --- a/src/client/mac/handler/exception_handler.cc +++ b/src/client/mac/handler/exception_handler.cc @@ -34,6 +34,20 @@ #include "client/mac/handler/minidump_generator.h" #include "common/mac/macho_utilities.h" +#ifndef USE_PROTECTED_ALLOCATIONS +#define USE_PROTECTED_ALLOCATIONS 0 +#endif + +// If USE_PROTECTED_ALLOCATIONS is activated then the +// gBreakpadAllocator needs to be setup in other code +// ahead of time. Please see ProtectedMemoryAllocator.h +// for more details. +#if USE_PROTECTED_ALLOCATIONS + #include "protected_memory_allocator.h" + extern ProtectedMemoryAllocator *gBreakpadAllocator; +#endif + + namespace google_breakpad { using std::map; @@ -360,6 +374,12 @@ void *ExceptionHandler::WaitForMessage(void *exception_handler_class) { MACH_RCV_MSG | MACH_RCV_LARGE, 0, sizeof(receive), self->handler_port_, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); + +#if USE_PROTECTED_ALLOCATIONS + if(gBreakpadAllocator) + gBreakpadAllocator->Unprotect(); +#endif + if (result == KERN_SUCCESS) { // Uninstall our handler so that we don't get in a loop if the process of // writing out a minidump causes an exception. However, if the exception @@ -426,7 +446,13 @@ void *ExceptionHandler::WaitForMessage(void *exception_handler_class) { bool ExceptionHandler::InstallHandler() { try { +#if USE_PROTECTED_ALLOCATIONS + previous_ = new (gBreakpadAllocator->Allocate(sizeof(ExceptionParameters)) ) + ExceptionParameters(); +#else previous_ = new ExceptionParameters(); +#endif + } catch (std::bad_alloc) { return false; @@ -472,7 +498,11 @@ bool ExceptionHandler::UninstallHandler(bool in_exception) { // this delete should NOT happen if an exception just occurred! if (!in_exception) { +#if USE_PROTECTED_ALLOCATIONS + previous_->~ExceptionParameters(); +#else delete previous_; +#endif } previous_ = NULL; diff --git a/src/client/mac/handler/protected_memory_allocator.cc b/src/client/mac/handler/protected_memory_allocator.cc new file mode 100644 index 00000000..10768541 --- /dev/null +++ b/src/client/mac/handler/protected_memory_allocator.cc @@ -0,0 +1,92 @@ +// 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(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; +} diff --git a/src/client/mac/handler/protected_memory_allocator.h b/src/client/mac/handler/protected_memory_allocator.h new file mode 100644 index 00000000..ed4f51d5 --- /dev/null +++ b/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(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_; + int next_alloc_offset_; + bool valid_; +}; + +#endif // PROTECTED_MEMORY_ALLOCATOR_H__ |