diff options
author | Peter Collingbourne <peter@pcc.me.uk> | 2013-11-21 23:20:54 +0000 |
---|---|---|
committer | Peter Collingbourne <peter@pcc.me.uk> | 2013-11-21 23:20:54 +0000 |
commit | 934d1f83aecf8f01646f4b2a09167309a4c1bb8d (patch) | |
tree | cea4255ce4407d28e7730a269a982fdb48d5d8f8 /lib/Transforms/Instrumentation/DataFlowSanitizer.cpp | |
parent | cd5978a7f58194aced7dd4884953d0651ca90314 (diff) | |
download | llvm-934d1f83aecf8f01646f4b2a09167309a4c1bb8d.tar.gz llvm-934d1f83aecf8f01646f4b2a09167309a4c1bb8d.tar.bz2 llvm-934d1f83aecf8f01646f4b2a09167309a4c1bb8d.tar.xz |
Introduce two command-line flags for the instrumentation pass to control whether the labels of pointers should be ignored in load and store instructions
The new command line flags are -dfsan-ignore-pointer-label-on-store and -dfsan-ignore-pointer-label-on-load. Their default value matches the current labelling scheme.
Additionally, the function __dfsan_union_load is marked as readonly.
Patch by Lorenzo Martignoni!
Differential Revision: http://llvm-reviews.chandlerc.com/D2187
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195382 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Instrumentation/DataFlowSanitizer.cpp')
-rw-r--r-- | lib/Transforms/Instrumentation/DataFlowSanitizer.cpp | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp index 9b9e725cde..c539be93a7 100644 --- a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp +++ b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp @@ -96,6 +96,22 @@ static cl::opt<bool> ClArgsABI( cl::desc("Use the argument ABI rather than the TLS ABI"), cl::Hidden); +// Controls whether the pass includes or ignores the labels of pointers in load +// instructions. +static cl::opt<bool> ClCombinePointerLabelsOnLoad( + "dfsan-combine-pointer-labels-on-load", + cl::desc("Combine the label of the pointer with the label of the data when " + "loading from memory."), + cl::Hidden, cl::init(true)); + +// Controls whether the pass includes or ignores the labels of pointers in +// stores instructions. +static cl::opt<bool> ClCombinePointerLabelsOnStore( + "dfsan-combine-pointer-labels-on-store", + cl::desc("Combine the label of the pointer with the label of the data when " + "storing in memory."), + cl::Hidden, cl::init(false)); + static cl::opt<bool> ClDebugNonzeroLabels( "dfsan-debug-nonzero-labels", cl::desc("Insert calls to __dfsan_nonzero_label on observing a parameter, " @@ -505,6 +521,7 @@ bool DataFlowSanitizer::runOnModule(Module &M) { DFSanUnionLoadFn = Mod->getOrInsertFunction("__dfsan_union_load", DFSanUnionLoadFnTy); if (Function *F = dyn_cast<Function>(DFSanUnionLoadFn)) { + F->addAttribute(AttributeSet::FunctionIndex, Attribute::ReadOnly); F->addAttribute(AttributeSet::ReturnIndex, Attribute::ZExt); } DFSanUnimplementedFn = @@ -978,14 +995,15 @@ void DFSanVisitor::visitLoadInst(LoadInst &LI) { Align = 1; } IRBuilder<> IRB(&LI); - Value *LoadedShadow = - DFSF.loadShadow(LI.getPointerOperand(), Size, Align, &LI); - Value *PtrShadow = DFSF.getShadow(LI.getPointerOperand()); - Value *CombinedShadow = DFSF.DFS.combineShadows(LoadedShadow, PtrShadow, &LI); - if (CombinedShadow != DFSF.DFS.ZeroShadow) - DFSF.NonZeroChecks.insert(CombinedShadow); - - DFSF.setShadow(&LI, CombinedShadow); + Value *Shadow = DFSF.loadShadow(LI.getPointerOperand(), Size, Align, &LI); + if (ClCombinePointerLabelsOnLoad) { + Value *PtrShadow = DFSF.getShadow(LI.getPointerOperand()); + Shadow = DFSF.DFS.combineShadows(Shadow, PtrShadow, &LI); + } + if (Shadow != DFSF.DFS.ZeroShadow) + DFSF.NonZeroChecks.insert(Shadow); + + DFSF.setShadow(&LI, Shadow); } void DFSanFunction::storeShadow(Value *Addr, uint64_t Size, uint64_t Align, @@ -1050,8 +1068,13 @@ void DFSanVisitor::visitStoreInst(StoreInst &SI) { } else { Align = 1; } - DFSF.storeShadow(SI.getPointerOperand(), Size, Align, - DFSF.getShadow(SI.getValueOperand()), &SI); + + Value* Shadow = DFSF.getShadow(SI.getValueOperand()); + if (ClCombinePointerLabelsOnStore) { + Value *PtrShadow = DFSF.getShadow(SI.getPointerOperand()); + Shadow = DFSF.DFS.combineShadows(Shadow, PtrShadow, &SI); + } + DFSF.storeShadow(SI.getPointerOperand(), Size, Align, Shadow, &SI); } void DFSanVisitor::visitBinaryOperator(BinaryOperator &BO) { |