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author | Bill Wendling <isanbard@gmail.com> | 2013-07-12 22:25:20 +0000 |
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committer | Bill Wendling <isanbard@gmail.com> | 2013-07-12 22:25:20 +0000 |
commit | 8a50013cc23810aa3e1ac8da66764fbb2d96147e (patch) | |
tree | 101213d40e04c54fcc8c4d82eef0205e9847de89 /lib/CodeGen/StackProtector.cpp | |
parent | 6383ef98fae2bab4595c6c36394093b7ad4a5597 (diff) | |
download | llvm-8a50013cc23810aa3e1ac8da66764fbb2d96147e.tar.gz llvm-8a50013cc23810aa3e1ac8da66764fbb2d96147e.tar.bz2 llvm-8a50013cc23810aa3e1ac8da66764fbb2d96147e.tar.xz |
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
Diffstat (limited to 'lib/CodeGen/StackProtector.cpp')
-rw-r--r-- | lib/CodeGen/StackProtector.cpp | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp index 1f673ab037..bf5d0c7d9e 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 <cstdlib> 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<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)) |