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// Copyright (c) 2012 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.
#ifndef COURGETTE_PATCHER_X86_32_H_
#define COURGETTE_PATCHER_X86_32_H_
#include <stdint.h>
#include "base/logging.h"
#include "base/macros.h"
#include "courgette/courgette_flow.h"
#include "courgette/ensemble.h"
#include "courgette/region.h"
#include "courgette/streams.h"
namespace courgette {
// PatcherX86_32 is the universal patcher for all executables. The executable
// type is determined by the program detector.
class PatcherX86_32 : public TransformationPatcher {
public:
explicit PatcherX86_32(const Region& region)
: ensemble_region_(region),
base_offset_(0),
base_length_(0) {
}
Status Init(SourceStream* parameter_stream) {
if (!parameter_stream->ReadVarint32(&base_offset_))
return C_BAD_TRANSFORM;
if (!parameter_stream->ReadVarint32(&base_length_))
return C_BAD_TRANSFORM;
if (base_offset_ > ensemble_region_.length())
return C_BAD_TRANSFORM;
if (base_length_ > ensemble_region_.length() - base_offset_)
return C_BAD_TRANSFORM;
return C_OK;
}
Status PredictTransformParameters(SinkStreamSet* predicted_parameters) {
// No code needed to write an 'empty' predicted parameter set.
return C_OK;
}
Status Transform(SourceStreamSet* corrected_parameters,
SinkStreamSet* transformed_element) {
if (!corrected_parameters->Empty())
return C_GENERAL_ERROR; // Don't expect any corrected parameters.
CourgetteFlow flow;
RegionBuffer only_buffer(
Region(ensemble_region_.start() + base_offset_, base_length_));
flow.ReadDisassemblerFromBuffer(flow.ONLY, only_buffer);
flow.CreateAssemblyProgramFromDisassembler(flow.ONLY, false);
flow.CreateEncodedProgramFromDisassemblerAndAssemblyProgram(flow.ONLY);
flow.DestroyAssemblyProgram(flow.ONLY);
flow.DestroyDisassembler(flow.ONLY);
flow.WriteSinkStreamSetFromEncodedProgram(flow.ONLY, transformed_element);
if (flow.failed())
LOG(ERROR) << flow.message();
return flow.status();
}
Status Reform(SourceStreamSet* transformed_element,
SinkStream* reformed_element) {
CourgetteFlow flow;
flow.ReadEncodedProgramFromSourceStreamSet(flow.ONLY, transformed_element);
flow.WriteExecutableFromEncodedProgram(flow.ONLY, reformed_element);
if (flow.failed())
LOG(ERROR) << flow.message();
return flow.status();
}
private:
Region ensemble_region_;
uint32_t base_offset_;
uint32_t base_length_;
DISALLOW_COPY_AND_ASSIGN(PatcherX86_32);
};
} // namespace courgette
#endif // COURGETTE_PATCHER_X86_32_H_