From 8a50013cc23810aa3e1ac8da66764fbb2d96147e Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Fri, 12 Jul 2013 22:25:20 +0000 Subject: [PATCH] Use the function attributes to pass along the stack protector buffer size. Now that we have robust function attributes, don't use a command line option to specify the stack protecto buffer size. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186217 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/CommandFlags.h | 4 ---- include/llvm/Target/TargetOptions.h | 7 +------ lib/CodeGen/StackProtector.cpp | 26 +++++++++++++++++++------- tools/llc/llc.cpp | 1 - tools/lto/LTOModule.cpp | 6 ------ tools/opt/opt.cpp | 1 - 6 files changed, 20 insertions(+), 25 deletions(-) diff --git a/include/llvm/CodeGen/CommandFlags.h b/include/llvm/CodeGen/CommandFlags.h index 9a27661b519..fd1d67bdcd1 100644 --- a/include/llvm/CodeGen/CommandFlags.h +++ b/include/llvm/CodeGen/CommandFlags.h @@ -220,8 +220,4 @@ cl::opt StartAfter("start-after", cl::value_desc("pass-name"), cl::init("")); -cl::opt -SSPBufferSize("stack-protector-buffer-size", cl::init(8), - cl::desc("Lower bound for a buffer to be considered for " - "stack protection")); #endif diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h index e240a9aeed2..04b20801066 100644 --- a/include/llvm/Target/TargetOptions.h +++ b/include/llvm/Target/TargetOptions.h @@ -48,7 +48,7 @@ namespace llvm { UseSoftFloat(false), NoZerosInBSS(false), JITEmitDebugInfo(false), JITEmitDebugInfoToDisk(false), GuaranteedTailCallOpt(false), DisableTailCalls(false), - StackAlignmentOverride(0), RealignStack(true), SSPBufferSize(0), + StackAlignmentOverride(0), RealignStack(true), EnableFastISel(false), PositionIndependentExecutable(false), EnableSegmentedStacks(false), UseInitArray(false), TrapFuncName(""), FloatABIType(FloatABI::Default), AllowFPOpFusion(FPOpFusion::Standard) @@ -151,10 +151,6 @@ namespace llvm { /// automatically realigned, if needed. unsigned RealignStack : 1; - /// SSPBufferSize - The minimum size of buffers that will receive stack - /// smashing protection when -fstack-protection is used. - unsigned SSPBufferSize; - /// EnableFastISel - This flag enables fast-path instruction selection /// which trades away generated code quality in favor of reducing /// compile time. @@ -224,7 +220,6 @@ inline bool operator==(const TargetOptions &LHS, ARE_EQUAL(DisableTailCalls) && ARE_EQUAL(StackAlignmentOverride) && ARE_EQUAL(RealignStack) && - ARE_EQUAL(SSPBufferSize) && ARE_EQUAL(EnableFastISel) && ARE_EQUAL(PositionIndependentExecutable) && ARE_EQUAL(EnableSegmentedStacks) && diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp index 1f673ab0377..bf5d0c7d9ec 100644 --- a/lib/CodeGen/StackProtector.cpp +++ b/lib/CodeGen/StackProtector.cpp @@ -33,6 +33,7 @@ #include "llvm/Pass.h" #include "llvm/Support/CommandLine.h" #include "llvm/Target/TargetLowering.h" +#include using namespace llvm; STATISTIC(NumFunProtected, "Number of functions protected"); @@ -53,6 +54,10 @@ namespace { DominatorTree *DT; + /// \brief The minimum size of buffers that will receive stack smashing + /// protection when -fstack-protection is used. + unsigned SSPBufferSize; + /// VisitedPHIs - The set of PHI nodes visited when determining /// if a variable's reference has been taken. This set /// is maintained to ensure we don't visit the same PHI node multiple @@ -85,11 +90,12 @@ namespace { bool RequiresStackProtector(); public: static char ID; // Pass identification, replacement for typeid. - StackProtector() : FunctionPass(ID), TM(0), TLI(0) { + StackProtector() : FunctionPass(ID), TM(0), TLI(0), SSPBufferSize(0) { initializeStackProtectorPass(*PassRegistry::getPassRegistry()); } StackProtector(const TargetMachine *TM) - : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()) { + : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()), + SSPBufferSize(8) { initializeStackProtectorPass(*PassRegistry::getPassRegistry()); } @@ -117,6 +123,12 @@ bool StackProtector::runOnFunction(Function &Fn) { if (!RequiresStackProtector()) return false; + Attribute Attr = + Fn.getAttributes().getAttribute(AttributeSet::FunctionIndex, + "ssp-buffer-size"); + if (Attr.isStringAttribute()) + SSPBufferSize = atoi(Attr.getValueAsString().data()); + ++NumFunProtected; return InsertStackProtectors(); } @@ -132,7 +144,6 @@ bool StackProtector::ContainsProtectableArray(Type *Ty, bool Strong, // protector if (Strong) return true; - const TargetMachine &TM = TLI->getTargetMachine(); if (!AT->getElementType()->isIntegerTy(8)) { // If we're on a non-Darwin platform or we're inside of a structure, don't // add stack protectors unless the array is a character array. @@ -142,7 +153,7 @@ bool StackProtector::ContainsProtectableArray(Type *Ty, bool Strong, // If an array has more than SSPBufferSize bytes of allocated space, then we // emit stack protectors. - if (TM.Options.SSPBufferSize <= TLI->getDataLayout()->getTypeAllocSize(AT)) + if (SSPBufferSize <= TLI->getDataLayout()->getTypeAllocSize(AT)) return true; } @@ -230,13 +241,14 @@ bool StackProtector::RequiresStackProtector() { if (const ConstantInt *CI = dyn_cast(AI->getArraySize())) { - unsigned BufferSize = TLI->getTargetMachine().Options.SSPBufferSize; - if (CI->getLimitedValue(BufferSize) >= BufferSize) + if (CI->getLimitedValue(SSPBufferSize) >= SSPBufferSize) // A call to alloca with size >= SSPBufferSize requires // stack protectors. return true; - } else // A call to alloca with a variable size requires protectors. + } else { + // A call to alloca with a variable size requires protectors. return true; + } } if (ContainsProtectableArray(AI->getAllocatedType(), Strong)) diff --git a/tools/llc/llc.cpp b/tools/llc/llc.cpp index bcabafc4675..9f6be81fc92 100644 --- a/tools/llc/llc.cpp +++ b/tools/llc/llc.cpp @@ -280,7 +280,6 @@ static int compileModule(char **argv, LLVMContext &Context) { Options.PositionIndependentExecutable = EnablePIE; Options.EnableSegmentedStacks = SegmentedStacks; Options.UseInitArray = UseInitArray; - Options.SSPBufferSize = SSPBufferSize; OwningPtr target(TheTarget->createTargetMachine(TheTriple.getTriple(), diff --git a/tools/lto/LTOModule.cpp b/tools/lto/LTOModule.cpp index 6220dd1c566..5ee43ba0229 100644 --- a/tools/lto/LTOModule.cpp +++ b/tools/lto/LTOModule.cpp @@ -151,11 +151,6 @@ UseInitArray("use-init-array", cl::desc("Use .init_array instead of .ctors."), cl::init(false)); -static cl::opt -SSPBufferSize("stack-protector-buffer-size", cl::init(8), - cl::desc("Lower bound for a buffer to be considered for " - "stack protection")); - LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t) : _module(m), _target(t), _context(_target->getMCAsmInfo(), _target->getRegisterInfo(), NULL), @@ -261,7 +256,6 @@ void LTOModule::getTargetOptions(TargetOptions &Options) { Options.PositionIndependentExecutable = EnablePIE; Options.EnableSegmentedStacks = SegmentedStacks; Options.UseInitArray = UseInitArray; - Options.SSPBufferSize = SSPBufferSize; } LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer, diff --git a/tools/opt/opt.cpp b/tools/opt/opt.cpp index 6fc8d6759b9..fa1cd436176 100644 --- a/tools/opt/opt.cpp +++ b/tools/opt/opt.cpp @@ -510,7 +510,6 @@ static TargetOptions GetTargetOptions() { Options.PositionIndependentExecutable = EnablePIE; Options.EnableSegmentedStacks = SegmentedStacks; Options.UseInitArray = UseInitArray; - Options.SSPBufferSize = SSPBufferSize; return Options; } -- 2.34.1