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-rw-r--r--src/client/mac/handler/exception_handler.cc30
-rw-r--r--src/client/mac/handler/protected_memory_allocator.cc92
-rw-r--r--src/client/mac/handler/protected_memory_allocator.h85
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__