SPIRV-Tools/source/fuzz/fuzzer.cpp
Alastair Donaldson 001e823b65
Add fuzzer pass to obfuscate constants. (#2671)
Adds a new transformation that can replace a constant with a uniform known to have the same value, and adds a fuzzer pass that (a) replaces a boolean with a comparison of literals (e.g. replacing "true" with "42 > 24"), and then (b) obfuscates the literals appearing in this comparison by replacing them with identically-valued uniforms, if available.

The fuzzer_replayer test file has also been updated to allow initial facts to be provided, and to do error checking of the status results returned by the fuzzer and replayer components.
2019-06-18 18:41:08 +01:00

134 lines
4.9 KiB
C++

// Copyright (c) 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/fuzz/fuzzer.h"
#include <cassert>
#include <sstream>
#include "source/fuzz/fact_manager.h"
#include "source/fuzz/fuzzer_context.h"
#include "source/fuzz/fuzzer_pass_add_dead_breaks.h"
#include "source/fuzz/fuzzer_pass_add_useful_constructs.h"
#include "source/fuzz/fuzzer_pass_obfuscate_constants.h"
#include "source/fuzz/fuzzer_pass_permute_blocks.h"
#include "source/fuzz/fuzzer_pass_split_blocks.h"
#include "source/fuzz/protobufs/spirvfuzz_protobufs.h"
#include "source/fuzz/pseudo_random_generator.h"
#include "source/opt/build_module.h"
#include "source/spirv_fuzzer_options.h"
#include "source/util/make_unique.h"
namespace spvtools {
namespace fuzz {
namespace {
const uint32_t kIdBoundGap = 100;
}
struct Fuzzer::Impl {
explicit Impl(spv_target_env env) : target_env(env) {}
const spv_target_env target_env; // Target environment.
MessageConsumer consumer; // Message consumer.
};
Fuzzer::Fuzzer(spv_target_env env) : impl_(MakeUnique<Impl>(env)) {}
Fuzzer::~Fuzzer() = default;
void Fuzzer::SetMessageConsumer(MessageConsumer c) {
impl_->consumer = std::move(c);
}
Fuzzer::FuzzerResultStatus Fuzzer::Run(
const std::vector<uint32_t>& binary_in,
const protobufs::FactSequence& initial_facts,
std::vector<uint32_t>* binary_out,
protobufs::TransformationSequence* transformation_sequence_out,
spv_const_fuzzer_options options) const {
// Check compatibility between the library version being linked with and the
// header files being used.
GOOGLE_PROTOBUF_VERIFY_VERSION;
spvtools::SpirvTools tools(impl_->target_env);
if (!tools.IsValid()) {
impl_->consumer(SPV_MSG_ERROR, nullptr, {},
"Failed to create SPIRV-Tools interface; stopping.");
return Fuzzer::FuzzerResultStatus::kFailedToCreateSpirvToolsInterface;
}
// Initial binary should be valid.
if (!tools.Validate(&binary_in[0], binary_in.size())) {
impl_->consumer(SPV_MSG_ERROR, nullptr, {},
"Initial binary is invalid; stopping.");
return Fuzzer::FuzzerResultStatus::kInitialBinaryInvalid;
}
// Build the module from the input binary.
std::unique_ptr<opt::IRContext> ir_context = BuildModule(
impl_->target_env, impl_->consumer, binary_in.data(), binary_in.size());
assert(ir_context);
// Make a PRNG, either from a given seed or from a random device.
PseudoRandomGenerator random_generator(
options->has_random_seed ? options->random_seed
: static_cast<uint32_t>(std::random_device()()));
// The fuzzer will introduce new ids into the module. The module's id bound
// gives the smallest id that can be used for this purpose. We add an offset
// to this so that there is a sizeable gap between the ids used in the
// original module and the ids used for fuzzing, as a readability aid.
//
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/2541) consider the
// case where the maximum id bound is reached.
auto minimum_fresh_id = ir_context->module()->id_bound() + kIdBoundGap;
FuzzerContext fuzzer_context(&random_generator, minimum_fresh_id);
FactManager fact_manager;
if (!fact_manager.AddFacts(initial_facts, ir_context.get())) {
return Fuzzer::FuzzerResultStatus::kInitialFactsInvalid;
}
// Add some essential ingredients to the module if they are not already
// present, such as boolean constants.
FuzzerPassAddUsefulConstructs(ir_context.get(), &fact_manager,
&fuzzer_context, transformation_sequence_out)
.Apply();
// Apply some semantics-preserving passes.
FuzzerPassSplitBlocks(ir_context.get(), &fact_manager, &fuzzer_context,
transformation_sequence_out)
.Apply();
FuzzerPassAddDeadBreaks(ir_context.get(), &fact_manager, &fuzzer_context,
transformation_sequence_out)
.Apply();
FuzzerPassObfuscateConstants(ir_context.get(), &fact_manager, &fuzzer_context,
transformation_sequence_out)
.Apply();
// Finally, give the blocks in the module a good shake-up.
FuzzerPassPermuteBlocks(ir_context.get(), &fact_manager, &fuzzer_context,
transformation_sequence_out)
.Apply();
// Encode the module as a binary.
ir_context->module()->ToBinary(binary_out, false);
return Fuzzer::FuzzerResultStatus::kComplete;
}
} // namespace fuzz
} // namespace spvtools