| // Copyright (c) 2020 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_pass_add_composite_inserts.h" |
| |
| #include "source/fuzz/fuzzer_util.h" |
| #include "source/fuzz/instruction_descriptor.h" |
| #include "source/fuzz/pseudo_random_generator.h" |
| #include "source/fuzz/transformation_composite_insert.h" |
| |
| namespace spvtools { |
| namespace fuzz { |
| |
| FuzzerPassAddCompositeInserts::FuzzerPassAddCompositeInserts( |
| opt::IRContext* ir_context, TransformationContext* transformation_context, |
| FuzzerContext* fuzzer_context, |
| protobufs::TransformationSequence* transformations) |
| : FuzzerPass(ir_context, transformation_context, fuzzer_context, |
| transformations) {} |
| |
| void FuzzerPassAddCompositeInserts::Apply() { |
| ForEachInstructionWithInstructionDescriptor( |
| [this](opt::Function* function, opt::BasicBlock* block, |
| opt::BasicBlock::iterator instruction_iterator, |
| const protobufs::InstructionDescriptor& instruction_descriptor) |
| -> void { |
| assert(instruction_iterator->opcode() == |
| instruction_descriptor.target_instruction_opcode() && |
| "The opcode of the instruction we might insert before must be " |
| "the same as the opcode in the descriptor for the instruction"); |
| |
| // Randomly decide whether to try adding an OpCompositeInsert |
| // instruction. |
| if (!GetFuzzerContext()->ChoosePercentage( |
| GetFuzzerContext()->GetChanceOfAddingCompositeInsert())) { |
| return; |
| } |
| |
| // It must be possible to insert an OpCompositeInsert instruction |
| // before |instruction_iterator|. |
| if (!fuzzerutil::CanInsertOpcodeBeforeInstruction( |
| SpvOpCompositeInsert, instruction_iterator)) { |
| return; |
| } |
| |
| // Look for available values that have composite type. |
| std::vector<opt::Instruction*> available_composites = |
| FindAvailableInstructions( |
| function, block, instruction_iterator, |
| [instruction_descriptor]( |
| opt::IRContext* ir_context, |
| opt::Instruction* instruction) -> bool { |
| // |instruction| must be a supported instruction of composite |
| // type. |
| if (!TransformationCompositeInsert:: |
| IsCompositeInstructionSupported(ir_context, |
| instruction)) { |
| return false; |
| } |
| |
| auto instruction_type = ir_context->get_type_mgr()->GetType( |
| instruction->type_id()); |
| |
| // No components of the composite can have type |
| // OpTypeRuntimeArray. |
| if (ContainsRuntimeArray(*instruction_type)) { |
| return false; |
| } |
| |
| // No components of the composite can be pointers. |
| // TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3658): |
| // Structs can have components of pointer type. |
| // FindOrCreateZeroConstant cannot be called on a |
| // pointer. We ignore pointers for now. Consider adding |
| // support for pointer types. |
| if (ContainsPointer(*instruction_type)) { |
| return false; |
| } |
| |
| return true; |
| }); |
| |
| // If there are no available values, then return. |
| if (available_composites.empty()) { |
| return; |
| } |
| |
| // Choose randomly one available composite value. |
| auto available_composite = |
| available_composites[GetFuzzerContext()->RandomIndex( |
| available_composites)]; |
| |
| // Take a random component of the chosen composite value. If the chosen |
| // component is itself a composite, then randomly decide whether to take |
| // its component and repeat. |
| uint32_t current_node_type_id = available_composite->type_id(); |
| std::vector<uint32_t> path_to_replaced; |
| while (true) { |
| auto current_node_type_inst = |
| GetIRContext()->get_def_use_mgr()->GetDef(current_node_type_id); |
| uint32_t num_of_components = fuzzerutil::GetBoundForCompositeIndex( |
| *current_node_type_inst, GetIRContext()); |
| |
| // If the composite is empty, then end the iteration. |
| if (num_of_components == 0) { |
| break; |
| } |
| uint32_t one_selected_index = |
| GetFuzzerContext()->GetRandomIndexForCompositeInsert( |
| num_of_components); |
| |
| // Construct a final index by appending the current index. |
| path_to_replaced.push_back(one_selected_index); |
| current_node_type_id = fuzzerutil::WalkOneCompositeTypeIndex( |
| GetIRContext(), current_node_type_id, one_selected_index); |
| |
| // If the component is not a composite then end the iteration. |
| if (!fuzzerutil::IsCompositeType( |
| GetIRContext()->get_type_mgr()->GetType( |
| current_node_type_id))) { |
| break; |
| } |
| |
| // If the component is a composite, but we decide not to go deeper, |
| // then end the iteration. |
| if (!GetFuzzerContext()->ChoosePercentage( |
| GetFuzzerContext() |
| ->GetChanceOfGoingDeeperToInsertInComposite())) { |
| break; |
| } |
| } |
| |
| // Look for available objects that have the type id |
| // |current_node_type_id| and can be inserted. |
| std::vector<opt::Instruction*> available_objects = |
| FindAvailableInstructions( |
| function, block, instruction_iterator, |
| [instruction_descriptor, current_node_type_id]( |
| opt::IRContext* /*unused*/, |
| opt::Instruction* instruction) -> bool { |
| if (instruction->result_id() == 0 || |
| instruction->type_id() == 0) { |
| return false; |
| } |
| if (instruction->type_id() != current_node_type_id) { |
| return false; |
| } |
| return true; |
| }); |
| |
| // If there are no objects of the specific type available, check if |
| // FindOrCreateZeroConstant can be called and create a zero constant of |
| // this type. |
| uint32_t available_object_id; |
| if (available_objects.empty()) { |
| if (!fuzzerutil::CanCreateConstant(GetIRContext(), |
| current_node_type_id)) { |
| return; |
| } |
| available_object_id = |
| FindOrCreateZeroConstant(current_node_type_id, false); |
| } else { |
| available_object_id = |
| available_objects[GetFuzzerContext()->RandomIndex( |
| available_objects)] |
| ->result_id(); |
| } |
| auto new_result_id = GetFuzzerContext()->GetFreshId(); |
| |
| // Insert an OpCompositeInsert instruction which copies |
| // |available_composite| and in the copy inserts the object |
| // of type |available_object_id| at index |index_to_replace|. |
| ApplyTransformation(TransformationCompositeInsert( |
| instruction_descriptor, new_result_id, |
| available_composite->result_id(), available_object_id, |
| path_to_replaced)); |
| }); |
| } |
| |
| bool FuzzerPassAddCompositeInserts::ContainsPointer( |
| const opt::analysis::Type& type) { |
| switch (type.kind()) { |
| case opt::analysis::Type::kPointer: |
| return true; |
| case opt::analysis::Type::kArray: |
| return ContainsPointer(*type.AsArray()->element_type()); |
| case opt::analysis::Type::kMatrix: |
| return ContainsPointer(*type.AsMatrix()->element_type()); |
| case opt::analysis::Type::kVector: |
| return ContainsPointer(*type.AsVector()->element_type()); |
| case opt::analysis::Type::kStruct: |
| return std::any_of(type.AsStruct()->element_types().begin(), |
| type.AsStruct()->element_types().end(), |
| [](const opt::analysis::Type* element_type) { |
| return ContainsPointer(*element_type); |
| }); |
| default: |
| return false; |
| } |
| } |
| |
| bool FuzzerPassAddCompositeInserts::ContainsRuntimeArray( |
| const opt::analysis::Type& type) { |
| switch (type.kind()) { |
| case opt::analysis::Type::kRuntimeArray: |
| return true; |
| case opt::analysis::Type::kStruct: |
| // If any component of a struct is of type OpTypeRuntimeArray, return |
| // true. |
| return std::any_of(type.AsStruct()->element_types().begin(), |
| type.AsStruct()->element_types().end(), |
| [](const opt::analysis::Type* element_type) { |
| return ContainsRuntimeArray(*element_type); |
| }); |
| default: |
| return false; |
| } |
| } |
| |
| } // namespace fuzz |
| } // namespace spvtools |
