6024e5c395
clang 20.0.0 (based on r547379) from build 12806354. Bug: http://b/379133546 Test: N/A Change-Id: I2eb8938af55d809de674be63cb30cf27e801862b Upstream-Commit: ad834e67b1105d15ef907f6255d4c96e8e733f57
138 lines
4.2 KiB
C++
138 lines
4.2 KiB
C++
//===- StackProtector.h - Stack Protector Insertion -------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass inserts stack protectors into functions which need them. A variable
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// with a random value in it is stored onto the stack before the local variables
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// are allocated. Upon exiting the block, the stored value is checked. If it's
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// changed, then there was some sort of violation and the program aborts.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_STACKPROTECTOR_H
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#define LLVM_CODEGEN_STACKPROTECTOR_H
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#include "llvm/Analysis/DomTreeUpdater.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/Pass.h"
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#include "llvm/TargetParser/Triple.h"
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namespace llvm {
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class BasicBlock;
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class Function;
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class Module;
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class TargetLoweringBase;
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class TargetMachine;
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class SSPLayoutInfo {
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friend class StackProtectorPass;
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friend class SSPLayoutAnalysis;
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friend class StackProtector;
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static constexpr unsigned DefaultSSPBufferSize = 8;
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/// A mapping of AllocaInsts to their required SSP layout.
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using SSPLayoutMap =
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DenseMap<const AllocaInst *, MachineFrameInfo::SSPLayoutKind>;
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/// Layout - Mapping of allocations to the required SSPLayoutKind.
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/// StackProtector analysis will update this map when determining if an
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/// AllocaInst triggers a stack protector.
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SSPLayoutMap Layout;
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/// The minimum size of buffers that will receive stack smashing
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/// protection when -fstack-protection is used.
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unsigned SSPBufferSize = DefaultSSPBufferSize;
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bool RequireStackProtector = false;
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// A prologue is generated.
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bool HasPrologue = false;
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// IR checking code is generated.
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bool HasIRCheck = false;
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public:
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// Return true if StackProtector is supposed to be handled by SelectionDAG.
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bool shouldEmitSDCheck(const BasicBlock &BB) const;
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void copyToMachineFrameInfo(MachineFrameInfo &MFI) const;
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};
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class SSPLayoutAnalysis : public AnalysisInfoMixin<SSPLayoutAnalysis> {
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friend AnalysisInfoMixin<SSPLayoutAnalysis>;
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using SSPLayoutMap = SSPLayoutInfo::SSPLayoutMap;
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static AnalysisKey Key;
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public:
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using Result = SSPLayoutInfo;
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Result run(Function &F, FunctionAnalysisManager &FAM);
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/// Check whether or not \p F needs a stack protector based upon the stack
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/// protector level.
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static bool requiresStackProtector(Function *F,
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SSPLayoutMap *Layout = nullptr);
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};
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class StackProtectorPass : public PassInfoMixin<StackProtectorPass> {
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const TargetMachine *TM;
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public:
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explicit StackProtectorPass(const TargetMachine *TM) : TM(TM) {}
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PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM);
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};
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class StackProtector : public FunctionPass {
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private:
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/// A mapping of AllocaInsts to their required SSP layout.
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using SSPLayoutMap = SSPLayoutInfo::SSPLayoutMap;
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const TargetMachine *TM = nullptr;
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Function *F = nullptr;
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Module *M = nullptr;
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std::optional<DomTreeUpdater> DTU;
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SSPLayoutInfo LayoutInfo;
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public:
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static char ID; // Pass identification, replacement for typeid.
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StackProtector();
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SSPLayoutInfo &getLayoutInfo() { return LayoutInfo; }
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void getAnalysisUsage(AnalysisUsage &AU) const override;
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// Return true if StackProtector is supposed to be handled by SelectionDAG.
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bool shouldEmitSDCheck(const BasicBlock &BB) const {
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return LayoutInfo.shouldEmitSDCheck(BB);
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}
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bool runOnFunction(Function &Fn) override;
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void copyToMachineFrameInfo(MachineFrameInfo &MFI) const {
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LayoutInfo.copyToMachineFrameInfo(MFI);
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}
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/// Check whether or not \p F needs a stack protector based upon the stack
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/// protector level.
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static bool requiresStackProtector(Function *F,
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SSPLayoutMap *Layout = nullptr) {
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return SSPLayoutAnalysis::requiresStackProtector(F, Layout);
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}
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};
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} // end namespace llvm
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#endif // LLVM_CODEGEN_STACKPROTECTOR_H
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