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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 Bill Wendling 6 years ago
6 changed file(s) with 20 addition(s) and 25 deletion(s). Raw diff Collapse all Expand all
219219 cl::value_desc("pass-name"),
220220 cl::init(""));
221221
222 cl::opt
223 SSPBufferSize("stack-protector-buffer-size", cl::init(8),
224 cl::desc("Lower bound for a buffer to be considered for "
225 "stack protection"));
226222 #endif
4747 UseSoftFloat(false), NoZerosInBSS(false),
4848 JITEmitDebugInfo(false), JITEmitDebugInfoToDisk(false),
4949 GuaranteedTailCallOpt(false), DisableTailCalls(false),
50 StackAlignmentOverride(0), RealignStack(true), SSPBufferSize(0),
50 StackAlignmentOverride(0), RealignStack(true),
5151 EnableFastISel(false), PositionIndependentExecutable(false),
5252 EnableSegmentedStacks(false), UseInitArray(false), TrapFuncName(""),
5353 FloatABIType(FloatABI::Default), AllowFPOpFusion(FPOpFusion::Standard)
149149 /// RealignStack - This flag indicates whether the stack should be
150150 /// automatically realigned, if needed.
151151 unsigned RealignStack : 1;
152
153 /// SSPBufferSize - The minimum size of buffers that will receive stack
154 /// smashing protection when -fstack-protection is used.
155 unsigned SSPBufferSize;
156152
157153 /// EnableFastISel - This flag enables fast-path instruction selection
158154 /// which trades away generated code quality in favor of reducing
223219 ARE_EQUAL(DisableTailCalls) &&
224220 ARE_EQUAL(StackAlignmentOverride) &&
225221 ARE_EQUAL(RealignStack) &&
226 ARE_EQUAL(SSPBufferSize) &&
227222 ARE_EQUAL(EnableFastISel) &&
228223 ARE_EQUAL(PositionIndependentExecutable) &&
229224 ARE_EQUAL(EnableSegmentedStacks) &&
3232 #include "llvm/Pass.h"
3333 #include "llvm/Support/CommandLine.h"
3434 #include "llvm/Target/TargetLowering.h"
35 #include
3536 using namespace llvm;
3637
3738 STATISTIC(NumFunProtected, "Number of functions protected");
5152 Module *M;
5253
5354 DominatorTree *DT;
55
56 /// \brief The minimum size of buffers that will receive stack smashing
57 /// protection when -fstack-protection is used.
58 unsigned SSPBufferSize;
5459
5560 /// VisitedPHIs - The set of PHI nodes visited when determining
5661 /// if a variable's reference has been taken. This set
8489 bool RequiresStackProtector();
8590 public:
8691 static char ID; // Pass identification, replacement for typeid.
87 StackProtector() : FunctionPass(ID), TM(0), TLI(0) {
92 StackProtector() : FunctionPass(ID), TM(0), TLI(0), SSPBufferSize(0) {
8893 initializeStackProtectorPass(*PassRegistry::getPassRegistry());
8994 }
9095 StackProtector(const TargetMachine *TM)
91 : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()) {
96 : FunctionPass(ID), TM(TM), TLI(0), Trip(TM->getTargetTriple()),
97 SSPBufferSize(8) {
9298 initializeStackProtectorPass(*PassRegistry::getPassRegistry());
9399 }
94100
115121 TLI = TM->getTargetLowering();
116122
117123 if (!RequiresStackProtector()) return false;
124
125 Attribute Attr =
126 Fn.getAttributes().getAttribute(AttributeSet::FunctionIndex,
127 "ssp-buffer-size");
128 if (Attr.isStringAttribute())
129 SSPBufferSize = atoi(Attr.getValueAsString().data());
118130
119131 ++NumFunProtected;
120132 return InsertStackProtectors();
131143 // protector
132144 if (Strong)
133145 return true;
134 const TargetMachine &TM = TLI->getTargetMachine();
135146 if (!AT->getElementType()->isIntegerTy(8)) {
136147 // If we're on a non-Darwin platform or we're inside of a structure, don't
137148 // add stack protectors unless the array is a character array.
141152
142153 // If an array has more than SSPBufferSize bytes of allocated space, then we
143154 // emit stack protectors.
144 if (TM.Options.SSPBufferSize <= TLI->getDataLayout()->getTypeAllocSize(AT))
155 if (SSPBufferSize <= TLI->getDataLayout()->getTypeAllocSize(AT))
145156 return true;
146157 }
147158
229240
230241 if (const ConstantInt *CI =
231242 dyn_cast(AI->getArraySize())) {
232 unsigned BufferSize = TLI->getTargetMachine().Options.SSPBufferSize;
233 if (CI->getLimitedValue(BufferSize) >= BufferSize)
243 if (CI->getLimitedValue(SSPBufferSize) >= SSPBufferSize)
234244 // A call to alloca with size >= SSPBufferSize requires
235245 // stack protectors.
236246 return true;
237 } else // A call to alloca with a variable size requires protectors.
247 } else {
248 // A call to alloca with a variable size requires protectors.
238249 return true;
250 }
239251 }
240252
241253 if (ContainsProtectableArray(AI->getAllocatedType(), Strong))
279279 Options.PositionIndependentExecutable = EnablePIE;
280280 Options.EnableSegmentedStacks = SegmentedStacks;
281281 Options.UseInitArray = UseInitArray;
282 Options.SSPBufferSize = SSPBufferSize;
283282
284283 OwningPtr
285284 target(TheTarget->createTargetMachine(TheTriple.getTriple(),
150150 cl::desc("Use .init_array instead of .ctors."),
151151 cl::init(false));
152152
153 static cl::opt
154 SSPBufferSize("stack-protector-buffer-size", cl::init(8),
155 cl::desc("Lower bound for a buffer to be considered for "
156 "stack protection"));
157
158153 LTOModule::LTOModule(llvm::Module *m, llvm::TargetMachine *t)
159154 : _module(m), _target(t),
160155 _context(_target->getMCAsmInfo(), _target->getRegisterInfo(), NULL),
260255 Options.PositionIndependentExecutable = EnablePIE;
261256 Options.EnableSegmentedStacks = SegmentedStacks;
262257 Options.UseInitArray = UseInitArray;
263 Options.SSPBufferSize = SSPBufferSize;
264258 }
265259
266260 LTOModule *LTOModule::makeLTOModule(MemoryBuffer *buffer,
509509 Options.PositionIndependentExecutable = EnablePIE;
510510 Options.EnableSegmentedStacks = SegmentedStacks;
511511 Options.UseInitArray = UseInitArray;
512 Options.SSPBufferSize = SSPBufferSize;
513512 return Options;
514513 }
515514