#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetLowering.h"
+#include <cstdlib>
using namespace llvm;
STATISTIC(NumFunProtected, "Number of functions protected");
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
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());
}
if (!RequiresStackProtector()) return false;
+ Attribute Attr =
+ Fn.getAttributes().getAttribute(AttributeSet::FunctionIndex,
+ "stack-protector-buffer-size");
+ if (Attr.isStringAttribute())
+ SSPBufferSize = atoi(Attr.getValueAsString().data());
+
++NumFunProtected;
return InsertStackProtectors();
}
// 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.
// 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;
}
if (const ConstantInt *CI =
dyn_cast<ConstantInt>(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))