| /* |
| * Copyright 2014, The Android Open Source Project |
| * |
| * 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 "Log.h" |
| #include "RSTransforms.h" |
| #include "RSFunctionsList.h" |
| |
| #include <cstdlib> |
| |
| #include <llvm/IR/Instructions.h> |
| #include <llvm/IR/Module.h> |
| #include <llvm/IR/Function.h> |
| #include <llvm/Pass.h> |
| |
| namespace { // anonymous namespace |
| |
| // Create a Module pass that screens all the global functions in the |
| // module and check if any disallowed external function is accessible |
| // and potentially callable. |
| class RSScreenFunctionsPass : public llvm::ModulePass { |
| private: |
| static char ID; |
| |
| bool isPresent(const std::string &name) { |
| auto lower = std::lower_bound(stubList.begin(), |
| stubList.end(), |
| name); |
| |
| if (lower != stubList.end() && name.compare(*lower) == 0) |
| return true; |
| return false; |
| } |
| |
| bool isLegal(llvm::Function &F) { |
| // A global function symbol is legal if |
| // a. it has a body, i.e. is not empty or |
| // b. its name starts with "llvm." or |
| // c. it is present in the RS Functions list. |
| |
| if (!F.empty()) |
| return true; |
| |
| llvm::StringRef FName = F.getName(); |
| if (FName.startswith("llvm.")) |
| return true; |
| |
| if (isPresent(FName.str())) |
| return true; |
| |
| return false; |
| } |
| |
| public: |
| RSScreenFunctionsPass() |
| : ModulePass (ID) { |
| std::sort(stubList.begin(), stubList.end()); |
| } |
| |
| virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override { |
| AU.setPreservesAll(); |
| } |
| |
| bool runOnModule(llvm::Module &M) override { |
| bool failed = false; |
| |
| auto &FunctionList(M.getFunctionList()); |
| for(auto &F: FunctionList) { |
| if (!isLegal(F)) { |
| ALOGE("Call to function %s from RenderScript is disallowed\n", |
| F.getName().str().c_str()); |
| failed = true; |
| } |
| } |
| |
| if (failed) { |
| llvm::report_fatal_error("Use of undefined external function"); |
| } |
| |
| return false; |
| } |
| |
| }; |
| |
| } |
| |
| char RSScreenFunctionsPass::ID = 0; |
| |
| namespace bcc { |
| |
| llvm::ModulePass * |
| createRSScreenFunctionsPass() { |
| return new RSScreenFunctionsPass(); |
| } |
| |
| } |