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ASan: wrap mapping scale and offset in a struct and make it a member of ASan passes. Add test for non-default mapping scale and offset. No functionality change

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172610 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Alexey Samsonov 2013-01-16 13:23:28 +00:00
parent 2ce6eeb8ff
commit 19cd7e9ce2
2 changed files with 119 additions and 51 deletions
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129
lib/Transforms/Instrumentation/AddressSanitizer.cpp
View File

@ -53,7 +53,7 @@ using namespace llvm;
static const uint64_t kDefaultShadowScale = 3;
static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
static const uint64_t kDefaultShadowOffsetAndroid = 0;
static const uint64_t kDefaultShadowOffsetPie = 0;
static const size_t kMaxStackMallocSize = 1 << 16; // 64K
static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
@ -186,14 +186,38 @@ class SetOfDynamicallyInitializedGlobals {
SmallSet<GlobalValue*, 32> DynInitGlobals;
};
static int MappingScale() {
return ClMappingScale ? ClMappingScale : kDefaultShadowScale;
/// This struct defines the shadow mapping using the rule:
/// shadow = (mem >> Scale) + Offset.
struct ShadowMapping {
int Scale;
uint64_t Offset;
};
static ShadowMapping getShadowMapping(const Module &M, int LongSize) {
llvm::Triple targetTriple(M.getTargetTriple());
bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::Android;
ShadowMapping Mapping;
Mapping.Offset = isAndroid ? kDefaultShadowOffsetPie :
(LongSize == 32 ? kDefaultShadowOffset32 : kDefaultShadowOffset64);
if (ClMappingOffsetLog >= 0) {
// Zero offset log is the special case.
Mapping.Offset = (ClMappingOffsetLog == 0) ? 0 : 1ULL << ClMappingOffsetLog;
}
Mapping.Scale = kDefaultShadowScale;
if (ClMappingScale) {
Mapping.Scale = ClMappingScale;
}
return Mapping;
}
static size_t RedzoneSize() {
static size_t RedzoneSizeForScale(int MappingScale) {
// Redzone used for stack and globals is at least 32 bytes.
// For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
return std::max(32U, 1U << MappingScale());
return std::max(32U, 1U << MappingScale);
}
/// AddressSanitizer: instrument the code in module to find memory bugs.
@ -227,6 +251,7 @@ struct AddressSanitizer : public FunctionPass {
void createInitializerPoisonCalls(Module &M,
Value *FirstAddr, Value *LastAddr);
bool maybeInsertAsanInitAtFunctionEntry(Function &F);
void emitShadowMapping(Module &M, IRBuilder<> &IRB) const;
virtual bool doInitialization(Module &M);
static char ID; // Pass identification, replacement for typeid
@ -242,9 +267,9 @@ struct AddressSanitizer : public FunctionPass {
bool CheckLifetime;
LLVMContext *C;
DataLayout *TD;
uint64_t MappingOffset;
int LongSize;
Type *IntptrTy;
ShadowMapping Mapping;
Function *AsanCtorFunction;
Function *AsanInitFunction;
Function *AsanHandleNoReturnFunc;
@ -278,6 +303,9 @@ class AddressSanitizerModule : public ModulePass {
bool ShouldInstrumentGlobal(GlobalVariable *G);
void createInitializerPoisonCalls(Module &M, Value *FirstAddr,
Value *LastAddr);
size_t RedzoneSize() const {
return RedzoneSizeForScale(Mapping.Scale);
}
bool CheckInitOrder;
SmallString<64> BlacklistFile;
@ -286,6 +314,7 @@ class AddressSanitizerModule : public ModulePass {
Type *IntptrTy;
LLVMContext *C;
DataLayout *TD;
ShadowMapping Mapping;
Function *AsanPoisonGlobals;
Function *AsanUnpoisonGlobals;
Function *AsanRegisterGlobals;
@ -308,6 +337,7 @@ struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
LLVMContext *C;
Type *IntptrTy;
Type *IntptrPtrTy;
ShadowMapping Mapping;
SmallVector<AllocaInst*, 16> AllocaVec;
SmallVector<Instruction*, 8> RetVec;
@ -332,7 +362,8 @@ struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
: F(F), ASan(ASan), DIB(*F.getParent()), C(ASan.C),
IntptrTy(ASan.IntptrTy), IntptrPtrTy(PointerType::get(IntptrTy, 0)),
TotalStackSize(0), StackAlignment(1 << MappingScale()) {}
Mapping(ASan.Mapping),
TotalStackSize(0), StackAlignment(1 << Mapping.Scale) {}
bool runOnFunction() {
if (!ClStack) return false;
@ -411,6 +442,9 @@ struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
AI.getAllocatedType()->isSized());
}
size_t RedzoneSize() const {
return RedzoneSizeForScale(Mapping.Scale);
}
uint64_t getAllocaSizeInBytes(AllocaInst *AI) {
Type *Ty = AI->getAllocatedType();
uint64_t SizeInBytes = ASan.TD->getTypeAllocSize(Ty);
@ -473,12 +507,12 @@ static bool GlobalWasGeneratedByAsan(GlobalVariable *G) {
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
Shadow = IRB.CreateLShr(Shadow, MappingScale());
if (MappingOffset == 0)
Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
if (Mapping.Offset == 0)
return Shadow;
// (Shadow >> scale) | offset
return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy,
MappingOffset));
Mapping.Offset));
}
void AddressSanitizer::instrumentMemIntrinsicParam(
@ -614,7 +648,7 @@ Instruction *AddressSanitizer::generateCrashCode(
Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
Value *ShadowValue,
uint32_t TypeSize) {
size_t Granularity = 1 << MappingScale();
size_t Granularity = 1 << Mapping.Scale;
// Addr & (Granularity - 1)
Value *LastAccessedByte = IRB.CreateAnd(
AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
@ -635,7 +669,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
Type *ShadowTy = IntegerType::get(
*C, std::max(8U, TypeSize >> MappingScale()));
*C, std::max(8U, TypeSize >> Mapping.Scale));
Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
Value *ShadowPtr = memToShadow(AddrLong, IRB);
Value *CmpVal = Constant::getNullValue(ShadowTy);
@ -644,7 +678,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
size_t Granularity = 1 << MappingScale();
size_t Granularity = 1 << Mapping.Scale;
TerminatorInst *CrashTerm = 0;
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
@ -782,7 +816,9 @@ bool AddressSanitizerModule::runOnModule(Module &M) {
BL.reset(new BlackList(BlacklistFile));
if (BL->isIn(M)) return false;
C = &(M.getContext());
IntptrTy = Type::getIntNTy(*C, TD->getPointerSizeInBits());
int LongSize = TD->getPointerSizeInBits();
IntptrTy = Type::getIntNTy(*C, LongSize);
Mapping = getShadowMapping(M, LongSize);
initializeCallbacks(M);
DynamicallyInitializedGlobals.Init(M);
@ -930,6 +966,28 @@ void AddressSanitizer::initializeCallbacks(Module &M) {
/*hasSideEffects=*/true);
}
void AddressSanitizer::emitShadowMapping(Module &M, IRBuilder<> &IRB) const {
// Tell the values of mapping offset and scale to the run-time if they are
// specified by command-line flags.
if (ClMappingOffsetLog >= 0) {
GlobalValue *asan_mapping_offset =
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
ConstantInt::get(IntptrTy, Mapping.Offset),
kAsanMappingOffsetName);
// Read the global, otherwise it may be optimized away.
IRB.CreateLoad(asan_mapping_offset, true);
}
if (ClMappingScale) {
GlobalValue *asan_mapping_scale =
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
ConstantInt::get(IntptrTy, Mapping.Scale),
kAsanMappingScaleName);
// Read the global, otherwise it may be optimized away.
IRB.CreateLoad(asan_mapping_scale, true);
}
}
// virtual
bool AddressSanitizer::doInitialization(Module &M) {
// Initialize the private fields. No one has accessed them before.
@ -955,41 +1013,10 @@ bool AddressSanitizer::doInitialization(Module &M) {
AsanInitFunction->setLinkage(Function::ExternalLinkage);
IRB.CreateCall(AsanInitFunction);
llvm::Triple targetTriple(M.getTargetTriple());
bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::Android;
MappingOffset = isAndroid ? kDefaultShadowOffsetAndroid :
(LongSize == 32 ? kDefaultShadowOffset32 : kDefaultShadowOffset64);
if (ClMappingOffsetLog >= 0) {
if (ClMappingOffsetLog == 0) {
// special case
MappingOffset = 0;
} else {
MappingOffset = 1ULL << ClMappingOffsetLog;
}
}
if (ClMappingOffsetLog >= 0) {
// Tell the run-time the current values of mapping offset and scale.
GlobalValue *asan_mapping_offset =
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
ConstantInt::get(IntptrTy, MappingOffset),
kAsanMappingOffsetName);
// Read the global, otherwise it may be optimized away.
IRB.CreateLoad(asan_mapping_offset, true);
}
if (ClMappingScale) {
GlobalValue *asan_mapping_scale =
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
ConstantInt::get(IntptrTy, MappingScale()),
kAsanMappingScaleName);
// Read the global, otherwise it may be optimized away.
IRB.CreateLoad(asan_mapping_scale, true);
}
Mapping = getShadowMapping(M, LongSize);
emitShadowMapping(M, IRB);
appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
return true;
}
@ -1147,7 +1174,7 @@ void FunctionStackPoisoner::initializeCallbacks(Module &M) {
void FunctionStackPoisoner::poisonRedZones(
const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> IRB, Value *ShadowBase,
bool DoPoison) {
size_t ShadowRZSize = RedzoneSize() >> MappingScale();
size_t ShadowRZSize = RedzoneSize() >> Mapping.Scale;
assert(ShadowRZSize >= 1 && ShadowRZSize <= 4);
Type *RZTy = Type::getIntNTy(*C, ShadowRZSize * 8);
Type *RZPtrTy = PointerType::get(RZTy, 0);
@ -1178,13 +1205,13 @@ void FunctionStackPoisoner::poisonRedZones(
// Poison the partial redzone at right
Ptr = IRB.CreateAdd(
ShadowBase, ConstantInt::get(IntptrTy,
(Pos >> MappingScale()) - ShadowRZSize));
(Pos >> Mapping.Scale) - ShadowRZSize));
size_t AddressableBytes = RedzoneSize() - (AlignedSize - SizeInBytes);
uint32_t Poison = 0;
if (DoPoison) {
PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
RedzoneSize(),
1ULL << MappingScale(),
1ULL << Mapping.Scale,
kAsanStackPartialRedzoneMagic);
}
Value *PartialPoison = ConstantInt::get(RZTy, Poison);
@ -1193,7 +1220,7 @@ void FunctionStackPoisoner::poisonRedZones(
// Poison the full redzone at right.
Ptr = IRB.CreateAdd(ShadowBase,
ConstantInt::get(IntptrTy, Pos >> MappingScale()));
ConstantInt::get(IntptrTy, Pos >> Mapping.Scale));
bool LastAlloca = (i == AllocaVec.size() - 1);
Value *Poison = LastAlloca ? PoisonRight : PoisonMid;
IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));

41
test/Instrumentation/AddressSanitizer/different_scale_and_offset.ll Normal file
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@ -0,0 +1,41 @@
; Test non-default shadow mapping scale and offset.
;
; RUN: opt < %s -asan -asan-mapping-scale=2 -asan-mapping-offset-log=0 -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-unknown-linux-gnu"
; Test that ASan tells scale and offset to runtime.
; CHECK: @__asan_mapping_offset = linkonce_odr constant i64 0
; CHECK: @__asan_mapping_scale = linkonce_odr constant i64 2
define i32 @test_load(i32* %a) address_safety {
; CHECK: @test_load
; CHECK-NOT: load
; CHECK: %[[LOAD_ADDR:[^ ]*]] = ptrtoint i32* %a to i64
; CHECK: lshr i64 %[[LOAD_ADDR]], 2
; No need in shift for zero offset.
; CHECK-NOT: or i64
; CHECK: %[[LOAD_SHADOW_PTR:[^ ]*]] = inttoptr
; CHECK: %[[LOAD_SHADOW:[^ ]*]] = load i8* %[[LOAD_SHADOW_PTR]]
; CHECK: icmp ne i8
; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
; No need in slow path for i32 and mapping scale equal to 2.
; CHECK-NOT: and i64 %[[LOAD_ADDR]]
;
; The crash block reports the error.
; CHECK: call void @__asan_report_load4(i64 %[[LOAD_ADDR]])
; CHECK: unreachable
;
; The actual load.
; CHECK: %tmp1 = load i32* %a
; CHECK: ret i32 %tmp1
entry:
%tmp1 = load i32* %a
ret i32 %tmp1
}