mirror of
https://github.com/KhronosGroup/SPIRV-Tools
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3d4a0dd48f
This change ensures that global and local variables donated from other modules are always initialized at their declaration in the module being transformed. This is to help limit issues related to undefined behaviour that might arise due to accessing uninitialized memory. The change also introduces some helper functions in fuzzer_util to make it easier to find the pointee types of pointer types.
104 lines
3.7 KiB
C++
104 lines
3.7 KiB
C++
// Copyright (c) 2020 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "source/fuzz/transformation_load.h"
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#include "source/fuzz/fuzzer_util.h"
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#include "source/fuzz/instruction_descriptor.h"
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namespace spvtools {
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namespace fuzz {
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TransformationLoad::TransformationLoad(
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const spvtools::fuzz::protobufs::TransformationLoad& message)
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: message_(message) {}
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TransformationLoad::TransformationLoad(
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uint32_t fresh_id, uint32_t pointer_id,
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const protobufs::InstructionDescriptor& instruction_to_insert_before) {
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message_.set_fresh_id(fresh_id);
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message_.set_pointer_id(pointer_id);
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*message_.mutable_instruction_to_insert_before() =
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instruction_to_insert_before;
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}
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bool TransformationLoad::IsApplicable(
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opt::IRContext* context,
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const spvtools::fuzz::FactManager& /*unused*/) const {
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// The result id must be fresh.
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if (!fuzzerutil::IsFreshId(context, message_.fresh_id())) {
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return false;
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}
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// The pointer must exist and have a type.
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auto pointer = context->get_def_use_mgr()->GetDef(message_.pointer_id());
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if (!pointer || !pointer->type_id()) {
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return false;
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}
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// The type must indeed be a pointer type.
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auto pointer_type = context->get_def_use_mgr()->GetDef(pointer->type_id());
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assert(pointer_type && "Type id must be defined.");
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if (pointer_type->opcode() != SpvOpTypePointer) {
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return false;
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}
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// We do not want to allow loading from null or undefined pointers, as it is
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// not clear how punishing the consequences of doing so are from a semantics
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// point of view.
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switch (pointer->opcode()) {
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case SpvOpConstantNull:
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case SpvOpUndef:
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return false;
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default:
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break;
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}
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// Determine which instruction we should be inserting before.
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auto insert_before =
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FindInstruction(message_.instruction_to_insert_before(), context);
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// It must exist, ...
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if (!insert_before) {
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return false;
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}
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// ... and it must be legitimate to insert a store before it.
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if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpLoad, insert_before)) {
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return false;
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}
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// The pointer needs to be available at the insertion point.
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return fuzzerutil::IdIsAvailableBeforeInstruction(context, insert_before,
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message_.pointer_id());
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}
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void TransformationLoad::Apply(opt::IRContext* context,
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spvtools::fuzz::FactManager* /*unused*/) const {
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uint32_t result_type = fuzzerutil::GetPointeeTypeIdFromPointerType(
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context, fuzzerutil::GetTypeId(context, message_.pointer_id()));
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fuzzerutil::UpdateModuleIdBound(context, message_.fresh_id());
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FindInstruction(message_.instruction_to_insert_before(), context)
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->InsertBefore(MakeUnique<opt::Instruction>(
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context, SpvOpLoad, result_type, message_.fresh_id(),
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opt::Instruction::OperandList(
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{{SPV_OPERAND_TYPE_ID, {message_.pointer_id()}}})));
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context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
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}
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protobufs::Transformation TransformationLoad::ToMessage() const {
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protobufs::Transformation result;
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*result.mutable_load() = message_;
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return result;
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}
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} // namespace fuzz
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} // namespace spvtools
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