diff options
Diffstat (limited to 'llvm/lib')
-rw-r--r-- | llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp | 10 | ||||
-rw-r--r-- | llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp | 80 |
2 files changed, 57 insertions, 33 deletions
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp index 53dd96e205c..0902f355b08 100644 --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -2180,8 +2180,10 @@ void FunctionStackPoisoner::processStaticAllocas() { // Minimal header size (left redzone) is 4 pointers, // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms. size_t MinHeaderSize = ASan.LongSize / 2; - ASanStackFrameLayout L; - ComputeASanStackFrameLayout(SVD, 1ULL << Mapping.Scale, MinHeaderSize, &L); + const ASanStackFrameLayout &L = + ComputeASanStackFrameLayout(SVD, 1ULL << Mapping.Scale, MinHeaderSize); + const SmallVector<uint8_t, 64> &ShadowBytes = + GetShadowBytesAfterScope(SVD, L); DEBUG(dbgs() << L.DescriptionString << " --- " << L.FrameSize << "\n"); uint64_t LocalStackSize = L.FrameSize; bool DoStackMalloc = ClUseAfterReturn && !ASan.CompileKernel && @@ -2278,12 +2280,12 @@ void FunctionStackPoisoner::processStaticAllocas() { // Poison the stack redzones at the entry. Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB); - poisonStackFrame(L.ShadowBytes, IRB, ShadowBase, true); + poisonStackFrame(ShadowBytes, IRB, ShadowBase, true); auto UnpoisonStack = [&](IRBuilder<> &IRB) { // Do this always as poisonAlloca can be disabled with // detect_stack_use_after_scope=0. - poisonStackFrame(L.ShadowBytes, IRB, ShadowBase, false); + poisonStackFrame(ShadowBytes, IRB, ShadowBase, false); if (!StaticAllocaPoisonCallVec.empty()) { // If we poisoned some allocas in llvm.lifetime analysis, // unpoison whole stack frame now. diff --git a/llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp b/llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp index 8e2ff7f25a2..0cd6643278d 100644 --- a/llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp +++ b/llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp @@ -47,15 +47,14 @@ static size_t VarAndRedzoneSize(size_t Size, size_t Alignment) { return alignTo(Res, Alignment); } -void +ASanStackFrameLayout ComputeASanStackFrameLayout(SmallVectorImpl<ASanStackVariableDescription> &Vars, - size_t Granularity, size_t MinHeaderSize, - ASanStackFrameLayout *Layout) { + size_t Granularity, size_t MinHeaderSize) { assert(Granularity >= 8 && Granularity <= 64 && (Granularity & (Granularity - 1)) == 0); assert(MinHeaderSize >= 16 && (MinHeaderSize & (MinHeaderSize - 1)) == 0 && MinHeaderSize >= Granularity); - size_t NumVars = Vars.size(); + const size_t NumVars = Vars.size(); assert(NumVars > 0); for (size_t i = 0; i < NumVars; i++) Vars[i].Alignment = std::max(Vars[i].Alignment, kMinAlignment); @@ -64,13 +63,13 @@ ComputeASanStackFrameLayout(SmallVectorImpl<ASanStackVariableDescription> &Vars, SmallString<2048> StackDescriptionStorage; raw_svector_ostream StackDescription(StackDescriptionStorage); StackDescription << NumVars; - Layout->FrameAlignment = std::max(Granularity, Vars[0].Alignment); - SmallVector<uint8_t, 64> &SB(Layout->ShadowBytes); - SB.clear(); + + ASanStackFrameLayout Layout; + Layout.Granularity = Granularity; + Layout.FrameAlignment = std::max(Granularity, Vars[0].Alignment); size_t Offset = std::max(std::max(MinHeaderSize, Granularity), Vars[0].Alignment); assert((Offset % Granularity) == 0); - SB.insert(SB.end(), Offset / Granularity, kAsanStackLeftRedzoneMagic); for (size_t i = 0; i < NumVars; i++) { bool IsLast = i == NumVars - 1; size_t Alignment = std::max(Granularity, Vars[i].Alignment); @@ -78,7 +77,7 @@ ComputeASanStackFrameLayout(SmallVectorImpl<ASanStackVariableDescription> &Vars, size_t Size = Vars[i].Size; const char *Name = Vars[i].Name; assert((Alignment & (Alignment - 1)) == 0); - assert(Layout->FrameAlignment >= Alignment); + assert(Layout.FrameAlignment >= Alignment); assert((Offset % Alignment) == 0); assert(Size > 0); assert(Vars[i].LifetimeSize <= Size); @@ -87,31 +86,54 @@ ComputeASanStackFrameLayout(SmallVectorImpl<ASanStackVariableDescription> &Vars, size_t NextAlignment = IsLast ? Granularity : std::max(Granularity, Vars[i + 1].Alignment); size_t SizeWithRedzone = VarAndRedzoneSize(Vars[i].Size, NextAlignment); - size_t LifetimeShadowSize = - (Vars[i].LifetimeSize + Granularity - 1) / Granularity; - SB.insert(SB.end(), LifetimeShadowSize, kAsanStackUseAfterScopeMagic); - if (Size / Granularity >= LifetimeShadowSize) { - SB.insert(SB.end(), Size / Granularity - LifetimeShadowSize, 0); - if (Size % Granularity) - SB.insert(SB.end(), Size % Granularity); - } - SB.insert(SB.end(), (SizeWithRedzone - Size) / Granularity, - IsLast ? kAsanStackRightRedzoneMagic - : kAsanStackMidRedzoneMagic); Vars[i].Offset = Offset; Offset += SizeWithRedzone; - assert(Offset == SB.size() * Granularity); } if (Offset % MinHeaderSize) { - size_t ExtraRedzone = MinHeaderSize - (Offset % MinHeaderSize); - SB.insert(SB.end(), ExtraRedzone / Granularity, - kAsanStackRightRedzoneMagic); - Offset += ExtraRedzone; + Offset += MinHeaderSize - (Offset % MinHeaderSize); + } + Layout.DescriptionString = StackDescription.str(); + Layout.FrameSize = Offset; + assert((Layout.FrameSize % MinHeaderSize) == 0); + + return Layout; +} + +SmallVector<uint8_t, 64> +GetShadowBytes(const SmallVectorImpl<ASanStackVariableDescription> &Vars, + const ASanStackFrameLayout &Layout) { + SmallVector<uint8_t, 64> SB; + SB.clear(); + const size_t NumVars = Vars.size(); + assert(NumVars > 0); + const size_t Granularity = Layout.Granularity; + SB.resize(Vars[0].Offset / Granularity, kAsanStackLeftRedzoneMagic); + for (const auto &Var : Vars) { + SB.resize(Var.Offset / Granularity, kAsanStackMidRedzoneMagic); + + SB.resize(SB.size() + Var.Size / Granularity, 0); + if (Var.Size % Granularity) + SB.push_back(Var.Size % Granularity); } - Layout->DescriptionString = StackDescription.str(); - Layout->FrameSize = Offset; - assert((Layout->FrameSize % MinHeaderSize) == 0); - assert(Layout->FrameSize / Granularity == Layout->ShadowBytes.size()); + SB.resize(Layout.FrameSize / Granularity, kAsanStackRightRedzoneMagic); + return SB; +} + +SmallVector<uint8_t, 64> GetShadowBytesAfterScope( + const SmallVectorImpl<ASanStackVariableDescription> &Vars, + const ASanStackFrameLayout &Layout) { + SmallVector<uint8_t, 64> SB = GetShadowBytes(Vars, Layout); + const size_t Granularity = Layout.Granularity; + + for (const auto &Var : Vars) { + const size_t LifetimeShadowSize = + (Var.LifetimeSize + Granularity - 1) / Granularity; + const size_t Offset = Var.Offset / Granularity; + std::fill(SB.begin() + Offset, SB.begin() + Offset + LifetimeShadowSize, + kAsanStackUseAfterScopeMagic); + } + + return SB; } } // llvm namespace |